DEF 14A of Koppers Holdings Inc., Mar 27, 2026

DEF 14A of Koppers Holdings Inc.

Filed Mar 27, 2026 · FY20250001315257-26-000026

Open on EDGAR
  1. Board Nominees

    Board Nominees Current lead independent director Albert J. Neupaver will not stand for re-election to the board at the 2026 annual meeting. Under the retirement age criteria of our corporate governance guidelines, Mr. Neupaver is ineligible for re-election at this annual meeting, and he will retire from the board of directors effective at the 2026 annual meeting. Effective immediately following the 2026 annual meeting on May 7, 2026, the board has appointed Traci L. Jensen to serve as lead independent director. Following the annual meeting, the size of the board will be reduced to eight members.

  2. Board Nominees

    | | | | | Current Committee Memberships of Director Nominees | | | | | | Name | Age | Director Since | Independent | Audit | Management Development and Compensation | Nominating and Corporate Governance | Strategy and Risk(1) | Sustainability | | Leroy M. Ball (Chair) | 57 | 2015 | No | | | | | | | Xudong Feng, Ph.D. | 67 | 2009 | Yes | | | | | (Chair) | | Traci L. Jensen | 59 | 2018 | Yes | | | | | | | David L. Motley | 67 | 2018 | Yes | | | (Chair) | | | | Laura J. Posadas | 50 | 2025 | Yes | | | | | | | Andrew D. Sandifer | 56 | 2023 | Yes | (Chair) | | | | | | Nishan J. Vartanian | 66 | 2024 | Yes | | | | | | | Sonja M. Wilkerson | 65 | 2018 | Yes | | (Chair) | | | |

  3. Board Nominees

    (1)Mr. Neupaver served as chair of the strategy and risk committee in 2025 and is expected to continue serving in that role until his retirement from the board effective at the 2026 annual meeting.

  4. Board Nominees

    | vi | 2026 Proxy Statement |

  5. TABLE OF CONTENTS

    | PROXY STATEMENT | | 2025 Non-qualified Deferred Compensation .............. | 34 | | | | Potential Payments upon Termination or | | | PROXY SUMMARY | v | Change in Control ........................................................... | 35 | | General Information About This Annual | | Director Compensation ................................................... | 39 | | Meeting ............................................................................... | v | Stock Ownership Guidelines for Our Non- | | | Proposals to be Considered and Board Voting | | Employee Directors ......................................................... | 41 | | Recommendations ............................................................ | v | 2025 Pay Ratio Disclosure ............................................ | 41 | | Board Nominees ................................................................ | v | Compensation Committee Interlocks and | | | Board Nominee Skills and Experience Summary ........ | vi | Insider Participation ........................................................ | 42 | | 2025 Performance Highlights .......................................... | vii | 2025 Pay Versus Performance Disclosure .................. | 43 | | Executive Compensation Highlights ............................... | vii | | | | Corporate Governance Highlights .................................. | viii | TRANSACTIONS WITH RELATED | | | | | PERSONS | 47 | | PROXY ITEM 1 — PROPOSAL FOR ELECTION OF DIRECTORS | 1 | | | | | | LONG-TERM EQUITY INCENTIVE AWARD GRANT PRACTICES | 48 | | General ............................................................................... | 1 | | | | Vote Required .................................................................... | 1 | | | | Director Qualifications ...................................................... | 1 | AUDITORS | 49 | | Biographical Summaries of Director Nominees ............ | 3 | | | | Board Meetings and Committees ................................... | 7 | PROXY ITEM 2 — PROPOSAL TO APPROVE | | | | | AN AMENDMENT TO OUR AMENDED AND | | | CORPORATE GOVERNANCE MATTERS | 9 | RESTATED EMPLOYEE STOCK PURCHASE | | | Corporate Governance Guidelines ................................. | 9 | PLAN | 50 | | Director Independence ..................................................... | 9 | | | | Board Leadership Structure ............................................. | 10 | EQUITY COMPENSATION PLANS | 54 | | Executive Sessions ........................................................... | 11 | | | | Risk Oversight .................................................................... | 11 | PROXY ITEM 3 — PROPOSAL TO | | | Code of Conduct and Code of Ethics ............................. | 12 | APPROVE AN ADVISORY RESOLUTION | | | Sustainability ...................................................................... | 12 | ON OUR NAMED EXECUTIVE OFFICER | | | Communications with the Board ..................................... | 14 | COMPENSATION | 55 | | Nomination Procedures .................................................... | 14 | | | | Committee Reports to Shareholders .............................. | 15 | PROXY ITEM 4 — PROPOSAL TO | | | Audit Committee Report ............................................... | 15 | RATIFY THE APPOINTMENT OF | | | Management Development and | | KPMG LLP AS OUR INDEPENDENT | | | Compensation Committee Report .............................. | 15 | REGISTERED PUBLIC ACCOUNTING | | | | | FIRM FOR FISCAL YEAR 2026 | 56 | | COMMON STOCK OWNERSHIP | 16 | | | | Director and Executive Officer Stock | | GENERAL MATTERS | 57 | | Ownership .......................................................................... | 16 | Annual Meeting Q&A ...................................................... | 57 | | Beneficial Owners of More Than Five Percent ............. | 17 | Shareholder Proposals for the Next Annual | | | | | Meeting ............................................................................. | 61 | | EXECUTIVE AND DIRECTOR | | | | | COMPENSATION | 18 | APPENDIX A — PROPOSED FIRST | | | Compensation Discussion and Analysis ........................ | 18 | AMENDMENT TO KOPPERS HOLDINGS | | | Summary Compensation Table ....................................... | 29 | INC. AMENDED AND RESTATED | | | 2025 Grants of Plan Based Awards ............................... | 31 | EMPLOYEE STOCK PURCHASE PLAN | A-1 | | Outstanding Equity Awards at Fiscal Year- | | | | | End ...................................................................................... | 32 | APPENDIX B — UNAUDITED | | | 2025 Option Exercises and Stock Vested ..................... | 34 | RECONCILIATIONS OF NON-GAAP | | | | | FINANCIAL MEASURES | B-1 |

  6. DIRECTORS

    DIRECTORS

  7. PROXY ITEM 1 — PROPOSAL FOR ELECTION OF DIRECTORS

    PROXY ITEM 1 — PROPOSAL FOR ELECTION OF DIRECTORS Our nominating and corporate governance committee believes each member of our board of directors possesses the individual qualities necessary to serve on the company’s board of directors, including high personal and professional ethical standards and integrity, honesty and good values. Our directors are highly educated, have varied skills, backgrounds and experience, and extensive track records of success in what we believe are highly relevant positions with large international companies and major private and public institutions. They have each demonstrated an ability to exercise sound judgment and have exhibited a commitment of service to the company and to the board, and each of our directors possesses strong communication skills. In addition, we believe that each director brings the skills, experience and perspective that, when combined, creates a board that possesses the requirements necessary to oversee the company’s business. Each nominee’s particular experience, qualifications, attributes and skills that led the board to conclude that such nominee should serve as a director for the company are set forth below. The committee reviews the board membership criteria and modifies them as necessary each year. The board recommends a vote “FOR” the election of all eight director nominees.

  8. PROXY ITEM 1 — PROPOSAL FOR ELECTION OF DIRECTORS

    | KOPPERS HOLDINGS INC. | 3 |

  9. PROXY ITEM 1 — PROPOSAL FOR ELECTION OF DIRECTORS

    PROXY ITEM 1 — PROPOSAL FOR ELECTION OF DIRECTORS

  10. Biographical Summaries of Director Nominees

    Biographical Summaries of Director Nominees

  11. LEROY M. BALL

    LEROY M. BALL Experience, Qualifications, Attributes or Skills: Mr. Ball has served as Chief Executive Officer of the company and Koppers Inc., our wholly-owned subsidiary, since January 2024, and as Chair of the board of directors of the company, since May 2025. Mr. Ball previously served as President and Chief Executive Officer of the company and Koppers Inc. from January 2015 through December 2023. Mr. Ball has been a director of Koppers Inc. since May 2013. Mr. Ball has served as a director of ATI Inc., a publicly traded company and global manufacturer of technically advanced specialty materials and complex components, since February 2019, and as a director of Highmark Inc., a health insurance organization and independent licensee of the Blue Cross Blue Shield Association, since January 2023. Mr. Ball has significant leadership experience in global businesses and valuable financial expertise and experience. As the only current management representative on our board, Mr. Ball enhances board discussions by providing an insider’s perspective on the company’s business, operations and strategic direction and insight into all aspects of the company’s business. AGE: 57 DIRECTOR SINCE: 2015 COMMITTEES: •Sustainability

  12. Other Public Company

    Other Public Company Directorships: •ATI Inc. XUDONG FENG, PH.D. Experience, Qualifications, Attributes or Skills: Dr. Feng served as Director of Science and Technology and Global Analytical Sciences of PPG Industries, Inc., a publicly traded global supplier of paints, coatings, optical products, and specialty materials, from May 2020 to June 2023. From June 2018 to May 2020, Dr. Feng served as Director of Research, Industrial and Packaging Coatings of PPG Industries, Inc. Dr. Feng has served as sole owner of Double Stallion Consulting LLC since October 2025, through which she provides management and innovation consulting services. Dr. Feng holds a Ph.D. in inorganic chemistry, which has provided her with a strong technical background and expertise in the specialty chemicals industry. Dr. Feng’s technical and industry experience, her experience in risk management and regulatory compliance, and her knowledge of environmental risks and best practices, developed through her leadership positions with PPG Industries, Inc., The University of Chicago Pritzker School of Molecular Engineering, Bayer MaterialScience LLC and Lanxess Corporation, provide an invaluable perspective to the board’s discussions. AGE: 67 DIRECTOR SINCE: 2009 COMMITTEES: •Management Development and Compensation •Nominating and Corporate Governance •Sustainability (Chair)

  13. Other Public Company

    Other Public Company Directorships: •None

  14. Other Public Company

    | 4 | 2026 Proxy Statement |

  15. PROXY ITEM 1 — PROPOSAL FOR ELECTION OF DIRECTORS

    PROXY ITEM 1 — PROPOSAL FOR ELECTION OF DIRECTORS

  16. TRACI L. JENSEN

    TRACI L. JENSEN Experience, Qualifications, Attributes or Skills: Ms. Jensen served as Executive Vice President and Chief Administrative Officer of H.B. Fuller Company, a publicly traded global adhesives manufacturer, from December 2022 to December 2024. Ms. Jensen served as Vice President, Global Business Process Improvement at H.B. Fuller Company from January 2020 through December 2022, and as Senior Vice President, Global Construction Adhesives at H.B. Fuller Company from September 2016 to January 2020. Since January 2026, Ms. Jensen has served as a director of Teckrez, LLC, a private company that develops, markets and stocks tackifier resins and acrylic monomers. Additionally, Ms. Jensen serves on the Dean’s Council of the Indiana University Kelley School of Business, and previously served on the board of the H.B. Fuller Foundation and as Executive Committee Chairman on the Adhesives and Sealants Council. Ms. Jensen brings to the board robust experience in international operations within the chemicals industry and unique chemicals industry insights, developed through her leadership responsibilities in areas such as manufacturing, strategic sourcing, sales, marketing, research and development, mergers and acquisitions, and human resources. In particular, Ms. Jensen’s international expertise contributes to the board’s consideration of our global operations. AGE: 59 DIRECTOR SINCE: 2018 COMMITTEES: •Management Development and Compensation •Nominating and Corporate Governance •Strategy and Risk

  17. Other Public Company

    Other Public Company Directorships: •None

  18. DAVID L. MOTLEY

    DAVID L. MOTLEY Experience, Qualifications, Attributes or Skills: Mr. Motley has served as General Partner of BTN Ventures, a Pittsburgh, Pennsylvania- based venture fund, investing nationally in pre-seed and seed stage software companies, since January 2021. In addition, Mr. Motley has served as Managing Partner with BlueTree Venture Fund, a venture fund based in Pittsburgh, Pennsylvania, since April 2012, and as Chief Executive Officer and President of MCAPS, LLC, a professional services company, since January 2018. Mr. Motley is an experienced board member, having served as a director of F.N.B. Corporation, a public financial services corporation, since July 2013, and as a director of Coherent Corp., a publicly traded materials, networking and photonics company, since February 2021. Mr. Motley also served as a director of Deep Lake Capital Acquisition Corp., a formerly publicly listed special purpose acquisition company, from January 2021 to January 2023. During his corporate career, Mr. Motley has served in various leadership roles involving strategic planning, business group management, mergers and acquisitions and corporate portfolio management. With more than 30 years of experience across multiple industries, Mr. Motley began with technical roles with PPG Industries Chemicals Division and culminated in vice president and group management roles with Philips Respironics and Covidien, Inc. Mr. Motley also serves as board chair of SRI, Inc. (formerly known as Stanford Research Institute), one of the foremost research entities in the country. Mr. Motley’s knowledge and experience in corporate strategy, mergers and acquisitions and other corporate growth initiatives deliver valuable insight to the board and enhance Mr. Motley’s ability to evaluate these matters as a member of our board. AGE: 67 DIRECTOR SINCE: 2018 COMMITTEES: •Audit •Nominating and Corporate Governance (Chair) •Strategy and Risk

  19. Other Public Company

    Other Public Company Directorships: •F.N.B. Corporation •Coherent Corp.

  20. Other Public Company

    | KOPPERS HOLDINGS INC. | 5 |

  21. PROXY ITEM 1 — PROPOSAL FOR ELECTION OF DIRECTORS

    PROXY ITEM 1 — PROPOSAL FOR ELECTION OF DIRECTORS

  22. LAURA J. POSADAS

    LAURA J. POSADAS Experience, Qualifications, Attributes or Skills: Ms. Posadas has served as Chief Executive Officer of Canlak Coatings Inc., a formulator and manufacturer of high-quality wood coating systems, since October 2024. Ms. Posadas served as Chief Commercial Officer of Matrix Adhesives Group, a provider of advanced adhesive and sealant solutions, from January 2023 to October 2024, and as Regional President, Americas of Castrol for BP p.l.c., the global integrated energy company, from December 2019 to December 2022. Ms. Posadas also serves on the board of directors and chairs the advisory arm of Coqual, a global think tank that helps companies redesign how they work and lead. Ms. Posadas brings to the board more than twenty years of experience in global leadership roles within the specialty chemicals industry, through which she has demonstrated a proven ability to drive innovation, operational excellence and strategic growth. AGE: 50 DIRECTOR SINCE: 2025 COMMITTEES: •None

  23. Other Public Company

    Other Public Company Directorships: •None

  24. ANDREW D. SANDIFER

    ANDREW D. SANDIFER Experience, Qualifications, Attributes or Skills: Mr. Sandifer has served as Executive Vice President and Chief Financial Officer of FMC Corporation, a publicly traded global agricultural sciences company, since May 2018. Mr. Sandifer serves on the board of trustees of Germantown Academy, a private school near Philadelphia, Pennsylvania, where he is a member of the finance and audit committees. He was a member of the board of directors of Philabundance, the leading hunger relief organization in the Delaware Valley, from 2014 to 2022, serving as board treasurer and chair of the finance committee from 2017 to 2022. Mr. Sandifer brings to the board broad international business experience guiding organizations through major transitions, including mergers and acquisitions, strategic realignment, restructuring and enterprise resource planning system implementation. His experience spans multiple industry sectors, with an emphasis on technology-driven product and materials businesses. AGE: 56 DIRECTOR SINCE: 2023 COMMITTEES: •Audit (Chair) •Management Development and Compensation •Nominating and Corporate Governance

  25. Other Public Company

    Other Public Company Directorships: •None

  26. Other Public Company

    | 6 | 2026 Proxy Statement |

  27. PROXY ITEM 1 — PROPOSAL FOR ELECTION OF DIRECTORS

    PROXY ITEM 1 — PROPOSAL FOR ELECTION OF DIRECTORS

  28. NISHAN J. VARTANIAN

    NISHAN J. VARTANIAN Experience, Qualifications, Attributes or Skills: Mr. Vartanian has served as the Chairman of MSA Safety Incorporated (“MSA”), a publicly traded global developer, manufacturer and supplier of safety products and software that protect people and facility infrastructures, since May 2024. Since joining MSA in 1985, Mr. Vartanian has served in a variety of roles of increased responsibility, including as President of MSA North America, and Senior Vice President and President of MSA Americas. Mr. Vartanian served as the Chairman and Chief Executive Officer of MSA from June 2023 to May 2024 and as the Chairman, President and Chief Executive Officer of MSA from May 2020 to May 2023. Mr. Vartanian has served as a director of MSA since December 2017, and as a director of Highmark Health, a national blended health organization headquartered in Pittsburgh, Pennsylvania, since July 2024. Mr. Vartanian serves on the board of trustees for the International Association of Firefighters Foundation. He is also a director of the Federal Reserve Bank of Cleveland, Pittsburgh Branch. Mr. Vartanian brings to the board a wealth of first-hand knowledge and experience in global markets, with particular specialization in safety-related products and practices. He has extensive executive management experience in the manufacturing industry, including in the oversight and execution of business strategy, product development, marketing, sales and finance. AGE: 66 DIRECTOR SINCE: 2024 COMMITTEES: •Audit •Strategy and Risk •Sustainability

  29. Other Public Company

    Other Public Company Directorships: •MSA Safety Incorporated

  30. SONJA M. WILKERSON

    SONJA M. WILKERSON Experience, Qualifications, Attributes or Skills: Ms. Wilkerson has served as the Executive Vice President and Chief People Officer of Bloom Energy Corporation, a public company which designs, manufactures and sells solid-oxide fuel cell systems, since January 2019. From December 2016 to January 2019, Ms. Wilkerson served as the Senior Vice President, Human Resources, at Infinera Corporation, a vertically integrated packet-optical solutions provider serving the largest network operators in the world. From November 2014 to December 2016, Ms. Wilkerson served as Vice President, Human Resources, at Hewlett Packard Enterprise Company. From October 2004 to October 2014, Ms. Wilkerson served as Director, Human Resources, at Cisco Systems, Inc. Ms. Wilkerson brings years of wide-ranging, global experience having served in roles responsible for human resources, information technology and facilities management for both domestic and international operations. In addition, Ms. Wilkerson has led merger integration activities and successfully managed the joining of international cultures. Ms. Wilkerson’s depth of experience in human resources and talent development, especially with respect to planning for the workforce of the future, serves as a unique resource and valuable viewpoint in the board’s discussions. AGE: 65 DIRECTOR SINCE: 2018 COMMITTEES: •Management Development and Compensation (Chair) •Nominating and Corporate Governance •Sustainability

  31. Other Public Company

    Other Public Company Directorships: •None

  32. Other Public Company

    | KOPPERS HOLDINGS INC. | 7 |

  33. PROXY ITEM 1 — PROPOSAL FOR ELECTION OF DIRECTORS

    PROXY ITEM 1 — PROPOSAL FOR ELECTION OF DIRECTORS

  34. PROXY ITEM 1 — PROPOSAL FOR ELECTION OF DIRECTORS

    PROXY ITEM 1 — PROPOSAL FOR ELECTION OF DIRECTORS Number of 2025 Meetings: 4 Nominating and Corporate Governance Committee Chair:

  35. EXECUTIVE AND DIRECTOR COMPENSATION

    EXECUTIVE AND DIRECTOR COMPENSATION

  36. Named Executive Officers

    Named Executive Officers •Based upon our 2025 adjusted EBITDA and modified net working capital as a percentage of sales, our NEOs earned annual incentive awards at 53% of their individual target amounts. •Long-term incentives represented approximately 84% of our CEO’s 2025 Total Direct Compensation (as defined below), approximately 82% of which were in the form of performance-based awards. •Long-term incentives represented, on average, approximately 67% of our other NEOs’ 2025 Total Direct Compensation (as defined below), approximately 58% of which were in the form of performance-based awards.

  37. EXECUTIVE AND DIRECTOR COMPENSATION

    EXECUTIVE AND DIRECTOR COMPENSATION

  38. Executive Compensation Program Principles

    Executive Compensation Program Principles The committee considers the following principles when it makes compensation decisions: •Pay for Performance — A significant portion of the total compensation of our NEOs should be based on performance and be at risk of forfeiture. We pay our NEOs higher compensation when they exceed our goals and lower compensation when they do not meet our goals. •Support Business Strategy — Our compensation programs should be aligned with our short-term and long-term business strategies. •Pay Competitively — We believe that total compensation for our NEOs should generally approximate the market median at target performance. Market is defined as individuals holding comparable positions and producing similar results at companies that the committee selects as our peers based on similar industry, revenue and complexity. Our compensation peer group is listed below in the section called “Companies Used for Defining Competitive Compensation.” Compensation data from our compensation peer group is one of several factors that informs our judgment of appropriate parameters for compensation levels. We believe that over-reliance on strict benchmarking can result in compensation that is unrelated to the value delivered by our executive officers because strict benchmarking does not take into account the specific performance of the NEOs or any unique circumstances or strategic considerations.

  39. Compensation

    Compensation * Includes Rollover TSR PSUs. •Base Salary — Recognizes different levels of responsibility within the company and serves as the basis for establishing target payouts for annual cash incentives and long-term equity incentives. Base salaries achieve our objectives to attract and retain our executives. •Annual Incentive Plan or AIP — Variable annual cash awards based upon weighted adjusted EBITDA and modified net working capital as a percentage of sales ("modified NWC") performance. Annual cash incentives serve to emphasize business growth and profitability by linking executive pay to corporate performance. Annual cash incentives achieve our objectives of attracting, retaining, and engaging our executives and aligning our executives’ financial interests with those of our shareholders. For 2025, 100 percent of Mr. Ball's and two-thirds of our other NEOs' 2025 target total annual incentive

  40. EXECUTIVE AND DIRECTOR COMPENSATION

    EXECUTIVE AND DIRECTOR COMPENSATION opportunity was converted into an award of Rollover TSR PSUs (as defined below), the value of which was increased by 10 percent for our NEOs other than Mr. Ball, to account for the conversion from a one-year cash award to a three-year stock award. The conversion of the AIP from a one-year cash award to a three-year stock award was done to promote retention, to provide expense savings in 2025 as management implemented a long-term structural savings plan and to further align our executives' financial interests with our long-term financial goals and the interests of our shareholders. •Long-Term Equity Incentives — Comprised of PSUs with two multi-year performance objectives, each applicable to a portion of the awards, and RSUs. Long-term equity incentives focus executives on the achievement of long-term corporate goals and strengthen the retention value of our compensation program. Long-term equity incentives also achieve our objectives of attracting and engaging our executives and aligning our executives’ financial interests with those of our shareholders. In addition to the components outlined above, our compensation program also provides our executives with certain retirement benefits, certain perquisites and individual change in control agreements (as described in the “Potential Payments upon Termination or Change in Control” section beginning on page 35 below). While we do not consider these benefits key components of our compensation program, they do assist in achieving our compensation objectives of attracting and retaining talented executives.

  41. Our Compensation-Setting Process

    | Steps | When | | 1.Design Program — The program for the year is reviewed, including targeted levels of annual and long-term pay and fixed and incentive compensation. | End of 2024 | | 2.Establish Range of Compensation Opportunities — Incentive compensation opportunities are set based on corporate performance. Minimum, target, and maximum performance levels and payouts are established for incentive awards. | End of 2024 for long-term incentives Beginning of 2025 for annual incentives | | 3.Review Performance — Performance is reviewed and incentive pool amounts are approved which determines individual annual cash incentive amounts. Payout percentages for performance-based long-term equity awards are certified. | Beginning of 2026 |

  42. Our Compensation-Setting Process

    The committee may use its judgment to supplement, reduce or modify at any time the compensation intended to be paid or awarded to the NEOs. The committee believes that it is in the best interest of the company and its shareholders that the committee have sufficient latitude to recognize and reward superior performance, which is important to attract and retain talented executives, and to adjust awards to reflect the quality of the company’s financial performance. The committee did not exercise any such discretion this year. Overview of 2025 NEO Compensation. Our 2025 actual NEO compensation includes both short- and long-term incentives established using financial metrics. In addition to base salary, this structure, shown below, includes cash incentives and long- term equity incentives, comprised of PSUs and RSUs. The table below reflects, for each NEO, the total direct compensation (“Total Direct Compensation”) for 2025, computed in accordance with SEC regulations applicable to disclosure of NEO compensation in the Summary Compensation Table below minus amounts reported in the Summary Compensation Table for Changes in Nonqualified Deferred Compensation Earnings and All Other Compensation.

  43. EXECUTIVE AND DIRECTOR COMPENSATION

    EXECUTIVE AND DIRECTOR COMPENSATION

  44. EXECUTIVE AND DIRECTOR COMPENSATION

    | | | | Long-Term Incentive | | | | | NEO | Base Salary | Annual Cash Incentive | EBITDA PSUs | TSR PSUs(1) | RSUs | Total Direct Compensation | | Leroy M. Ball | $975,000 | $— | $914,075 | $3,317,705 | $914,044 | $6,120,824 | | Jimmi Sue Smith | 440,000 | 58,520 | 137,506 | 324,745 | 357,548 | 1,318,319 | | James A. Sullivan | 650,000 | 115,267 | 365,636 | 919,731 | 731,209 | 2,781,843 | | Stephanie L. Apostolou | 475,000 | 63,175 | 166,245 | 358,318 | 432,280 | 1,495,018 | | Stephen G. Lucas | 360,360 | 31,952 | 112,606 | 193,562 | 292,839 | 991,319 |

  45. EXECUTIVE AND DIRECTOR COMPENSATION

    (1)Includes the value of Rollover TSR PSUs (as defined below). As described in more detail below under Annual Cash Incentives, 100 percent of Mr. Ball's and two-thirds of our other NEOs' 2025 target total annual incentive opportunity was converted into an award of Rollover TSR PSUs, the value of which was increased by 10 percent for our NEOs other than Mr. Ball. The terms and conditions applicable to the Rollover TSR PSUs are set forth below under Long-Term Equity Incentives. Other than the retirement and termination provisions, the terms and conditions of the Rollover TSR PSUs are the same as the other TSR PSUs. Please see pages 36 and 37 for a description of such retirement and termination provisions. Please see our Summary Compensation Table on page 29 which also reports amounts for Changes in Nonqualified Deferred Compensation Earnings and All Other Compensation. For our CEO, Mr. Ball, approximately 84 percent of 2025 Total Direct Compensation is pay-at-risk, which is payable over time or determined based upon financial goals or performance achievements, and approximately 69 percent of 2025 Total Direct Compensation is determined based upon financial goals or performance achievements. For our other NEOs, on average approximately 71 percent of 2025 Total Direct Compensation is pay-at-risk and approximately 43 percent of 2025 Total Direct Compensation is determined based upon financial goals or performance achievements.

  46. 2025 Compensation Decisions and Performance

    (1)Effective January 1, 2025, a base salary increase of 8.0 percent was awarded to Ms. Apostolou to reflect her new responsibilities as Chief Legal and Sustainability Officer and Secretary, which is a role she assumed on January 1, 2025. Annual Cash Incentives. In early 2025, the committee approved and the board ratified our amended and restated annual incentive plan, which served as the company’s main annual cash incentive plan for salaried employees. Each participant’s target total annual incentive opportunity was based upon a percentage of base salary (125 percent of salary for Mr. Ball, 100 percent of salary for Mr. Sullivan, 75 percent of salary for Mses. Smith and Apostolou and 50 percent of salary for Mr. Lucas). One hundred percent of Mr. Ball's and two-thirds of our other NEOs' 2025 target total annual incentive opportunity was converted into an award of Rollover TSR PSUs (as defined below), the value of which was increased by 10 percent for our NEOs other than Mr. Ball. Accordingly, Mr. Ball did not receive a cash incentive payout for 2025. One-third of our other NEOs' 2025 target total annual incentive opportunity was structured as a cash incentive payout based upon the company’s performance in relation to the plan’s adjusted EBITDA and modified NWC targets, which had weights of 75 percent and 25 percent, respectively. Adjusted EBITDA, as measured under the annual incentive plan, is defined as earnings before interest, taxes, depreciation and amortization, as adjusted by the committee in its discretion to account for certain items, as set forth on Appendix B hereto. Modified NWC is defined as the difference between our current assets and current liabilities at December 31, 2025, divided by our total net sales for the year, excluding, among other items at the company’s discretion, current pension liabilities, current derivative assets and liabilities, last-in, first out ("LIFO") reserve and current debt. The terms and conditions applicable to the Rollover TSR PSUs are set forth below under Long-Term Equity Incentives.

  47. EXECUTIVE AND DIRECTOR COMPENSATION

    EXECUTIVE AND DIRECTOR COMPENSATION Taking all of these elements together, the committee’s framework for determining annual cash incentives for the NEOs can be expressed as follows:

  48. Payout Percentage

    Payout Percentage

  49. Payout Percentage

    Payout Percentage

  50. Incentive Award

    Incentive Award = X X + X 75%

  51. Weighting

    Weighting The committee established a target adjusted EBITDA performance level of $280.0 million along with a range of incentive payouts at threshold, target and maximum performance levels (with linear interpolation for performance in between such levels), with corresponding payout percentages, each as set forth below.

  52. Weighting

    | Adjusted EBITDA | Performance | % of Target | % of Payout | | Maximum | $320,000,000 | 114% | 200% | | Target | 280,000,000 | 100% | 100% | | Actual | 256,716,000 | 92% | 71% | | Threshold | 240,000,000 | 86% | 50% |

  53. Weighting

    The committee established a target modified NWC performance level of 21.0 percent along with a range of incentive payouts at threshold, target and maximum performance levels (with linear interpolation for performance in between such levels), with corresponding payout percentages, each as set forth below.

  54. Weighting

    | Modified NWC | Performance | % of Target | % of Payout | | Maximum | 18.9% | 90% | 200% | | Target | 21.0% | 100% | 100% | | Threshold | 23.1% | 110% | 50% | | Actual | 25.8% | 123% | —% |

  55. Weighting

    For 2025, the company achieved adjusted EBITDA performance of $256.7 million and modified NWC performance of 25.8 percent, as calculated for purposes of the annual incentive plan. This corresponded to achievement of 92 percent of target adjusted EBITDA performance and 123 percent of target modified NWC performance, with weightings of 75 percent and 25 percent, respectively. For the one-third of our NEOs' (other than Mr. Ball's) 2025 target total annual incentive opportunity that was structured as a cash incentive payout, this led to a payout level of 71 percent for the 75 percent of our annual incentive opportunity that was based on adjusted EBITDA and — percent for the 25 percent of our annual incentive opportunity that was based on modified NWC. Taken together, this resulted in a 53 percent payout level for the one-third of our NEOs' (other than Mr. Ball's) 2025 target total annual incentive opportunity that was structured as a cash incentive payout and the following annual cash incentive payments to our NEOs other than Mr. Ball:

  56. EXECUTIVE AND DIRECTOR COMPENSATION

    EXECUTIVE AND DIRECTOR COMPENSATION Long-Term Equity Incentives. In 2025, each NEO received his or her long-term incentive award in two primary forms (with the applicable weighting determined as described below): •PSUs – with a 75 percent weighting for Mr. Ball, a 50 percent weighting for Mr. Sullivan and a 35 percent weighting for our other NEOs, PSU payouts are determined by our performance over a three-year period based on two performance measures each applicable to a portion of the total award; and •RSUs – with a 25 percent weighting for Mr. Ball, a 50 percent weighting for Mr. Sullivan and a 65 percent weighting for our other NEOs, RSUs vest in four equal annual installments. A portion of the 2025 PSU awards are eligible to be earned based upon the company’s relative total shareholder return (“TSR”) performance (“TSR PSUs”). An additional performance measure, three-year cumulative adjusted EBITDA, also applies to a portion of our PSU awards (“EBITDA PSUs”). Equity awards are granted under our shareholder-approved Amended and Restated 2020 Long Term Incentive Plan (the “LTIP”). In addition to his or her long-term incentive award, and as noted above under Annual Cash Incentives, 100 percent of Mr. Ball's and two-thirds of our other NEOs' 2025 target total annual cash incentive opportunity was converted into a special TSR PSU award ("Rollover TSR PSUs"), the value of which was increased by 10 percent for our NEOs other than Mr. Ball. The table below summarizes the material terms and conditions of the 2025 long-term incentive awards and the Rollover TSR PSUs.

  57. EXECUTIVE AND DIRECTOR COMPENSATION

    | What objective did the award serve in 2025? | •PSUs aligned shareholder and management interests by focusing management on relative stock price appreciation and three-year cumulative adjusted EBITDA. •RSUs aligned shareholder and management interests and also help to retain participants (some of whom are currently eligible for retirement), as well as to attract the next generation of our senior management. | | When do the 2025 RSUs vest? | •Subject to certain retirement and termination provisions, RSUs vest in equal annual installments over four years. | | When do the 2025 PSUs vest? | •Subject to certain retirement and termination provisions, PSUs will vest, if and to the extent earned, if the participant remains in service through the third anniversary of the award date. •Other than the retirement and termination provisions, the terms and conditions of the Rollover TSR PSUs are the same as the other TSR PSUs. Please see pages 36 and 37 for a description of the retirement and termination provisions applicable to the TSR PSUs. | | How do we measure performance for the 2025 PSUs? | •A portion of the PSUs will be eligible to be earned if the company’s three-year cumulative adjusted EBITDA meets certain performance thresholds based on a range of adjusted EBITDA achieved over the relevant three-year measurement period. •A portion of the PSUs will be eligible to be earned in three separate tranches, each representing one-third of such portion, if the company’s TSR relative to the S&P Small Cap 600 Materials Index meets certain performance thresholds based on a range of relative TSR achieved over the relevant performance period. The first tranche will be earned, if at all, if the relevant threshold performance level is met at the end of a one-year performance period. The second tranche will be earned, if at all, if the relevant threshold performance level is met at the end of a two-year performance period and the third tranche will be earned, if at all, if the relevant threshold performance level is met at the end of a three-year performance period. •If the company’s TSR is negative over the three-year performance period, then the cumulative number of TSR PSUs that may vest for such three-year period will be capped at 150 percent of target. •If the company's stock price exceeds $65.00 per share on the earlier of the last day of the three-year performance period or the date of any change in control during the three-year performance period, then the portion of the TSR PSUs representing the excess in fair market value of such TSR PSUs over the fair market value of such TSR PSUs if the company's stock price was $65.00 per share will be forfeited. |

  58. EXECUTIVE AND DIRECTOR COMPENSATION

    Performance for EBITDA PSUs granted in 2025 is based on a range of adjusted EBITDA achieved over the relevant three-year measurement period as set forth in the following table:

  59. EXECUTIVE AND DIRECTOR COMPENSATION

    | Performance Level | Three-Year Cumulative Adjusted EBITDA | % of Units to Vest | | Maximum | ≥ $975,000,000 | 200% | | Target | $915,000,000 | 100% | | Threshold | $825,000,000 | 25% |

  60. EXECUTIVE AND DIRECTOR COMPENSATION

    | 24 | 2026 Proxy Statement |

  61. EXECUTIVE AND DIRECTOR COMPENSATION

    EXECUTIVE AND DIRECTOR COMPENSATION Performance for TSR PSUs granted in 2025 is based on a range of relative TSR achieved in each of the relevant performance periods as set forth in the following table:

  62. EXECUTIVE AND DIRECTOR COMPENSATION

    | Relative TSR | Performance | % of Units to Vest | | Outstanding | ≥ 80th percentile | 200% | | | 70th percentile | 150% | | Target | 50th percentile | 100% | | | 35th percentile | 50% | | Threshold | 25th percentile | 25% |

  63. EXECUTIVE AND DIRECTOR COMPENSATION

    The percentage vesting is interpolated on a straight-line basis for performance between levels above the threshold for both EBITDA PSUs and TSR PSUs. The target dollar value of all equity awards to each NEO is determined based upon a multiplier of base salary. Once the total dollar value of the awards is determined for each NEO, the actual number of PSUs and RSUs is determined for each NEO as follows:

  64. EXECUTIVE AND DIRECTOR COMPENSATION

    | | PSU | | RSU | | Named Executive Officer | EBITDA | TSR | | | Leroy M. Ball | 25% | 50% | 25% | | James A. Sullivan | 25% | 25% | 50% | | Other NEOs | 25% | 10% | 65% |

  65. EXECUTIVE AND DIRECTOR COMPENSATION

    The committee uses the closing price of our common stock on the NYSE on the grant date to determine the number of PSUs (assuming target achievement) and RSUs awarded. The granting of a combination of RSUs and PSUs falls within the range of peer group practices, has a strong performance orientation and aligns our long-term compensation with the company’s strategic plan. Results of TSR Performance-Based Restricted Stock Units. The table below summarizes the results of our outstanding TSR PSUs as of December 31, 2025. Our total shareholder return was measured against that of the S&P Small Cap 600 Materials Index (as described above) over the applicable three-year period, two-year period or one-year period as set forth below. Our percentile ranking on this performance measure determined the percentage of target shares (if any) that were earned for each tranche. If the company’s TSR is negative over the three-year performance period, then the cumulative number of units that may vest for such three-year period will be capped at 150.0 percent of target. The aggregate payout associated with the 2023 TSR PSUs which vested in January 2026 was 150.0 percent (aggregate payout of 158.2 percent was reduced to 150.0 percent due to the application of the payout cap for the company's negative TSR over the three-year performance period).

  66. EXECUTIVE AND DIRECTOR COMPENSATION

    | Performance Period | Relative TSR Performance - Percentile Rank | Percentage of Units to Vest | | 2025 TSR PSUs | | | | One-year period ending December 31, 2025 | 30th | 38.6% | | 2024 TSR PSUs | | | | Two-year period ending December 31, 2025 | 19th | 0.0% | | One-year period ending December 31, 2024 | 24th | 0.0% | | 2023 TSR PSUs | | | | Three-year period ending December 31, 2025 | 64th | 135.7% | | Two-year period ending December 31, 2024 | 66th | 138.8% | | One-year period ending December 31, 2023 | 87th | 200.0% |

  67. EXECUTIVE AND DIRECTOR COMPENSATION

    Transition Agreement with Ms. Smith in 2026. On January 5, 2026, we agreed with Ms. Smith that she would retire from her position as our Chief Financial Officer effective January 5, 2026. Ms. Smith served as our Treasurer until her separation from our service on February 28, 2026 (the "Interim Employment Period"). On March 9, 2026, Koppers Inc. ("KI"), a wholly-owned subsidiary of the company, and Ms. Smith entered into a transition agreement (the "Smith Transition Agreement"), effective as of March 17, 2026, in connection with Ms. Smith’s separation from our service. Pursuant to the Smith Transition Agreement, in exchange for Ms. Smith’s general release and waiver of claims, her employment and services during the Interim Employment Period and her agreement to provide transition services from her separation date through February 28, 2027 (the "Transition Period"), KI has agreed, among other things, to pay Ms. Smith $440,000, payable over the Transition Period and to allow Ms. Smith to remain eligible for her earned and unpaid 2025 annual cash incentive, based on actual business performance, which will be payable in a lump sum on or around April 4, 2026, which is the same time such annual cash incentive is paid to other

  68. EXECUTIVE AND DIRECTOR COMPENSATION

    | KOPPERS HOLDINGS INC. | 25 |

  69. EXECUTIVE AND DIRECTOR COMPENSATION

    EXECUTIVE AND DIRECTOR COMPENSATION executives. In addition, in consideration and conditioned upon her services during the Transition Period, KI has agreed to pay Ms. Smith $123,400 in the form of a lump sum cash payment (representing the value of the equity awards that Ms. Smith would have become vested in during the Transition Period) and $330,000, payable in a lump sum on or around April 8, 2027 (representing her target 2026 annual cash incentive opportunity she would have been eligible for during the Transition Period if she continued to be a full-time employee). Changes to Long-Term Equity Incentives for 2026. On December 4, 2025, the committee approved and the board ratified the following changes for 2026 grants of equity compensation to eligible employees, including our NEOs, under the LTIP: •The mix of equity awards granted to our CEO will consist of 80 percent PSUs and 20 percent RSUs. The mix of equity awards granted to our other NEOs will consist of 60 percent PSUs and 40 percent RSUs. As noted above, for 2025, the equity mix for our CEO and NEOs was as follows: 75 percent PSUs and 25 percent RSUs for Mr. Ball, 50 percent PSUs and 50 percent RSUs for Mr. Sullivan and 35 percent PSUs and 65 percent RSUs for our other NEOs. •A portion of our 2026 PSU awards will continue to be earned based upon financial performance, but instead of using three- year cumulative adjusted EBITDA as our metric, we will now use three-year cumulative adjusted EPS and three-year cumulative free cash flow, each with weightings of 50 percent. Adjusted EBITDA margin will then be used as a performance modifier (i.e., -25 percent to +25 percent of actual earned performance). Consistent with our 2025 PSU awards, a portion of the 2026 PSU awards remain eligible to be earned based upon the company’s relative TSR performance. We believe that these changes better align our long-term compensation with the company’s strategic plan and remain consistent and competitive with peer group practices. NEO Retirement Benefits. We maintain a 401(k) plan that permits U.S. salaried employees, including the NEOs, to contribute up to 60 percent of pay, subject to applicable limits for 401(k) plans. We match 100 percent of all salaried employee contributions to the 401(k) plan, including those of the NEOs, on the first three percent of an employee’s salary contributed to the plan and match 50 percent on the next two percent of an employee’s salary contributed to the plan. In order to remain competitive in the market for senior executive talent, we also maintain a supplemental benefit plan, which we refer to as the Benefit Restoration Plan, to restore employer non-elective contributions lost by certain U.S. highly-paid employees, including the NEOs, in our 401(k) plan under U.S. tax law. Under both plans, we make employer non-elective contributions tied to our financial performance. Employer contributions have not yet been made for 2025; however, we have assumed such contributions will be paid for 2025 consistent with past practice and the assumed amounts of such contributions are included in the tables below. Perquisites and Other Benefits. We provide a limited number of perquisites and other benefits to certain of our NEOs, which include club dues, parking and executive physicals. Additional details of the perquisites and other benefits we provide are more fully described in the footnotes to the “All Other Compensation” column of the Summary Compensation Table below. We provide these perquisites and other benefits to promote a healthy work/life balance and provide opportunities for developing business relationships. We believe they are important to our ability to attract and retain top-quality executive talent and are consistent with those provided to executives at other companies comparable to us. The costs associated with providing these benefits for our NEOs are reflected in the “All Other Compensation” column of the Summary Compensation Table below on page 29. Our NEOs also participate in the same standard salaried benefit plans as our other U.S. salaried employees. This includes a basic welfare benefits package consisting of medical, dental, vision, life and disability insurance and accident insurance plans, as well as flexible spending arrangements for health care, dependent care and transportation expenses. Our NEOs are provided certain protections in the event of their termination of employment under specified circumstances, including in connection with a change in control of the company. We believe that these protections serve our retention objectives by permitting our NEOs to maintain continued focus and dedication to their responsibilities in order to maximize shareholder value, including in the event of a transaction that could result in a change in control of the company.

  70. EXECUTIVE AND DIRECTOR COMPENSATION

    EXECUTIVE AND DIRECTOR COMPENSATION •We maintain the ability to clawback compensation in connection with a financial restatement. Role of Consultants. In accordance with its authority to retain advisors, in late 2024, the committee engaged Meridian Compensation Partners, LLC (“Meridian”) as outside consultants to advise the committee with respect to 2025 compensation design decisions. Meridian does not advise our management or receive any other compensation from us, except for performing valuations of TSR PSUs. In its role as independent advisor to the committee, Meridian provided advice to the committee from time to time on various executive compensation matters, including conducting an annual competitive compensation analysis, which Meridian prepared for the committee in late 2024. In compliance with the SEC and the NYSE disclosure requirements regarding the independence of compensation consultants, Meridian provided the committee with a completed questionnaire addressing each of the six independence factors enumerated in the SEC requirements. Their responses affirm the independence of Meridian and the partners, consultants, and employees who service the committee on executive compensation matters and governance issues. Companies Used for Defining Competitive Compensation. As stated above, one of the committee’s principles is to target the compensation of our NEOs within a range of the market median of our peer companies that were selected based on comparability in terms of industry, revenue and complexity. The revenue range for our 2025 peer group was $721 million to $3.958 billion (based on revenue for the last 12 months as of October 31, 2024), with the peer group consisting of companies in multiple related industries, including building products, commodity chemicals, forest products and specialty chemicals. In advance of its decisions regarding 2025 compensation, the committee reviewed with Meridian the 2024 peer group and, taking into account Meridian’s advice, confirmed that it continues to constitute an appropriate peer group for purposes of 2025 compensation decisions with the following recommended change: •Masonite International Corporation was acquired by Owens Corning (OC) in May 2024. Because compensation benchmarking data is no longer available for Masonite International Corporation, the committee removed it from the peer group for purposes of determining 2025 compensation. Accordingly, for purposes of 2025 compensation decisions, the peer group selected by the committee, in consultation with Meridian, consisted of the following:

  71. Peer Group

    Peer Group •American Woodmark Corporation (AMWD) •Apogee Enterprises, Inc. (APOG) •Armstrong World Industries, Inc.(AWI) •Cabot Corporation (CBT) •EnPro Industries, Inc. (NPO) •Gibraltar Industries, Inc. (ROCK) •The Greenbrier Companies, Inc.(GBX) •Granite Construction Incorporated (GVA) •H.B. Fuller Company (FUL) •Hillenbrand, Inc. (HI) •Innospec, Inc. (IOSP) •Minerals Technologies, Inc. (MTX) •Quaker Chemical Corporation (KWR) •Simpson Manufacturing Co., Inc.(SSD) •Standex International Corporation (SXI) •Stella-Jones, Inc. (SJ.TO) •Stepan Company (SCL) •Sterling Infrastructure, Inc. (STRL) •Tronox Holdings plc (TROX) Statistical regression was not used to adjust peer compensation data based on our revenue positioning relative to the peer group. Through its competitive assessment, Meridian determined that target cash compensation for the majority of our executives fell at or below the market median competitive range, while the target total compensation for 40 percent of our executives fell within market competitive range. Stock Ownership Requirements for Our Named Executive Officers. The committee and our board of directors have approved stock ownership requirements for senior executive management. The requirements apply to selected members of the management team, including all of the NEOs except Ms. Smith due to her retirement. The committee and our board of directors have also approved stock ownership guidelines, which apply to our non-employee directors, as described more fully below under “Stock Ownership Guidelines for Our Non-Employee Directors.” The stock ownership requirements were designed to achieve the following objectives: •demonstrate senior management’s commitment to and confidence in the company’s long-term prospects; •align senior management’s interests with those of our shareholders; •support a long-term focus; and •quantify our expectations with regard to ownership of our stock by our senior management.

  72. Peer Group

    | KOPPERS HOLDINGS INC. | 27 |

  73. EXECUTIVE AND DIRECTOR COMPENSATION

    EXECUTIVE AND DIRECTOR COMPENSATION Our stock ownership requirements require our officers to accumulate a specified number of shares expressed as a value of stock ownership that is a multiple of base salary. The required value of stock ownership is converted into a number of shares that is recalculated annually. Until the stock ownership level is achieved, members of the management team are required to retain 75 percent of the net profit shares (i.e., excluding shares used for the payment of taxes) received from exercising stock options, the vesting of RSUs and PSUs.

  74. EXECUTIVE AND DIRECTOR COMPENSATION

    | Position | | Ownership Requirement Multiple of Base Salary | | Chief Executive Officer and Chair of the Board of Directors | (Mr. Ball) | 6x | | President and Chief Transformation Officer | (Mr. Sullivan) | 4x | | Chief Legal and Sustainability Officer and Secretary; Senior Vice President, Culture and Engagement* | (Ms. Apostolou and Mr. Lucas) | 3x |

  75. EXECUTIVE AND DIRECTOR COMPENSATION

    *Ms. Smith was no longer subject to our stock ownership requirements effective January 5, 2026 upon her retirement from her position as our Chief Financial Officer. During fiscal year 2025, while Ms. Smith was serving as Chief Financial Officer and Treasurer, the stock ownership requirement applicable to her was 3x base salary. Unvested RSUs and shares owned outright by the executives and/or their spouses count toward meeting the requirements. Unvested PSUs and unexercised stock options do not count toward meeting the stock ownership requirements for our executives. All of our NEOs have achieved compliance with the target ownership level. Policy on Insider Trading, Derivative Transactions and Restrictions on Hedging Transactions. We maintain an Insider Trading and Securities Compliance Policy (the “Policy”) governing the purchase, sale, gift, or other disposition or transfer of our securities that applies to all employees, officers (including our NEOs), directors and other Koppers personnel. We also follow this Policy for the repurchase of our securities. We believe that the Policy is reasonably designed to promote compliance with insider trading laws, rules, and regulations and the listing standards of the NYSE. A copy of the Policy was filed as Exhibit 19 to our Annual Report on Form 10-K for the year ended December 31, 2025. The Policy also prohibits our employees, officers (including our NEOs), directors and other personnel from directly or indirectly engaging in the following types of transactions with respect to our securities: certain forms of hedging or monetization transactions, such as prepaid variable forward contracts, equity swaps, collars and exchange funds, that would allow a person to hedge or offset any decrease in the market value of our securities; short sales; transactions in publicly traded options; pledging our securities as collateral for a loan; or holding our securities in margin accounts or a brokerage account with a “margin feature” (unless the margin feature is not utilized, company securities are otherwise excluded from being pledged or the account holder does not engage in any transaction that results in a lien upon the company securities in the account). Clawback Policy. As required by the Dodd-Frank Wall Street Reform and Consumer Protection Act of 2010 (Dodd-Frank Act), we maintain a clawback policy, which requires that certain incentive compensation paid to any current or former executive officer, including our NEOs, will be subject to recoupment if (x) the incentive compensation was calculated based on financial statements that were required to be restated due to material noncompliance with financial reporting requirements, without regard to any fault or misconduct, and (y) that noncompliance resulted in overpayment of the incentive compensation within the three fiscal years preceding the fiscal year in which the restatement was required. Incentive compensation subject to the clawback policy consists of compensation that is granted, earned or vested based wholly or in part upon the attainment of a financial reporting measure (as defined in our clawback policy), including stock price and total shareholder return, on and after October 2, 2023. Change in Control Agreements. We have entered into separate change in control agreements with all NEOs. Each of these agreements is described in the “Potential Payments upon Termination or Change in Control” section beginning on page 35 below. Tax Considerations. For federal income tax purposes, cash compensation, such as base salary or annual cash incentive, is includible as ordinary compensation income when earned, unless deferred under a company-sponsored deferral plan. Deferrals under tax-qualified plans, such as a 401(k) plan, do not affect the timing of our tax deduction. Deferrals under non-qualified plans, the adoption of which have been approved by the board of directors, will result in the deferral of our compensation deduction until such time as the cash compensation is paid to the employee. Section 162(m) of the Internal Revenue Code generally places a $1 million annual deduction limit on compensation paid to “covered employees,” which includes our NEOs. The committee will — consistent with its past practice — design compensation programs that are intended to be in the best long-term interests of the company and our shareholders, with deductibility of compensation being one of several considerations taken into account. We do not provide our NEOs with a “gross-up” or other reimbursement payment for any tax liability that he or she might owe as a result of the application of Sections 280G, 4999, or 409A of the Internal Revenue Code. Sections 280G and 4999 of the Internal Revenue Code provide that executive officers, directors who hold significant equity interests in the company and certain other service providers may be subject to an excise tax if they receive payments or benefits in connection with a change in control of

  76. EXECUTIVE AND DIRECTOR COMPENSATION

    | 28 | 2026 Proxy Statement |

  77. EXECUTIVE AND DIRECTOR COMPENSATION

    EXECUTIVE AND DIRECTOR COMPENSATION the company that exceeds certain prescribed limits, and that the company, or a successor, may forfeit a deduction on the amounts subject to this additional tax. Section 409A of the Internal Revenue Code also imposes additional significant taxes on an executive officer, director or other service provider to the company in the event that he or she receives “deferred compensation” that does not meet certain requirements of Section 409A of the Internal Revenue Code. Accounting Considerations. When reviewing preliminary recommendations and in connection with approving the terms of a given incentive plan period, management and the committee review and consider the accounting implications of a given award, including the estimated expense and impact on EPS. We follow The Financial Accounting Standards Board Accounting Standards Codification Topic 718, or FASB ASC Topic 718, for our stock-based awards. FASB ASC Topic 718 requires companies to measure the compensation expense for all share-based payment awards made to employees and directors, including stock options, RSUs and PSUs, based on the grant date “fair value” of these awards. This calculation is performed for accounting purposes and reported in the compensation tables below for equity awards to our NEOs as required by the applicable SEC rules. FASB ASC Topic 718 also requires companies to recognize the compensation cost of their stock-based compensation awards in their income statements over the period that the recipient of such compensation is required to render service in exchange for the award.

  78. EXECUTIVE AND DIRECTOR COMPENSATION

    | KOPPERS HOLDINGS INC. | 29 |

  79. EXECUTIVE AND DIRECTOR COMPENSATION

    EXECUTIVE AND DIRECTOR COMPENSATION

  80. Summary Compensation Table

    Summary Compensation Table The following table and related footnotes describe the total compensation awarded to, earned by or paid to our NEOs for services rendered during fiscal years 2025, 2024 and 2023.

  81. Summary Compensation Table

    | Name and Principal Position | Year | Salary | Stock Awards(2) | Non-Equity Incentive Plan Compensation(3) | Change in Nonqualified Deferred Compensation Earnings(4) | All Other Compensation(5) | Total | | Leroy M. Ball | 2025 | $975,000 | $5,145,824 | $— | $844 | $236,576 | $6,358,244 | | Chief Executive Officer and Chair of the Board of Directors | 2024 | 961,538 | 3,847,177 | 899,563 | — | 171,244 | 5,879,522 | | | 2023 | 915,680 | 3,572,221 | 1,265,592 | — | 207,060 | 5,960,553 | | Jimmi Sue Smith | 2025 | $440,000 | $819,799 | $58,520 | $48 | $83,543 | $1,401,910 | | Chief Financial Officer and Treasurer (Now Retired) | 2024 | 429,231 | 527,210 | 233,400 | — | 70,527 | 1,260,368 | | | 2023 | 393,269 | 502,973 | 278,100 | — | 75,777 | 1,250,119 | | James A. Sullivan | 2025 | $650,000 | $2,016,576 | $115,267 | $270 | $128,095 | $2,910,208 | | President and Chief Transformation Officer | 2024 | 650,000 | 1,542,263 | 505,700 | — | 110,764 | 2,808,727 | | | 2023 | 583,577 | 1,287,777 | 741,600 | — | 112,050 | 2,725,004 | | Stephanie L. Apostolou | 2025 | $475,000 | $956,843 | $63,175 | $58 | $77,870 | $1,572,946 | | Chief Legal and Sustainability Officer and Secretary | 2024 | 429,231 | 527,210 | 233,400 | — | 59,587 | 1,249,428 | | | 2023 | 389,231 | 482,920 | 266,976 | — | 60,398 | 1,199,525 | | Stephen G. Lucas(1) | 2025 | $360,360 | $599,007 | $31,952 | $14 | $49,689 | $1,041,022 | | Senior Vice President, Culture and Engagement | 2024 | 356,628 | 456,782 | 107,831 | — | 176,229 | 1,097,470 |

  82. Summary Compensation Table

    (1)Mr. Lucas was not an NEO in 2023. (2)The amounts shown in these columns represent the aggregate grant date fair value of RSUs and PSUs granted to our NEOs computed in accordance with FASB ASC Topic 718. The value of TSR PSUs disclosed in the table is based upon a Monte Carlo valuation model and the value of the EBITDA PSUs is based on the probable outcome of the performance measures on the grant date. These award grant date fair values have been determined using the assumptions underlying the valuation of equity awards set forth in note 8 of the consolidated financial statements in our Annual Reports on Form 10-K for the years ended December 31, 2025, December 31, 2024 and December 31, 2023. Assuming the maximum amount of shares underlying each PSU are earned and vested (based on our relative TSR performance and achievement of cumulative adjusted EBITDA goals), the grant date fair values of PSUs granted in 2025 are: Mr. Ball, $8,463,561; Ms. Smith, $924,503; Mr. Sullivan, $2,570,735; Ms. Apostolou, $1,049,125; and Mr. Lucas, $612,336. (3)As discussed above in the “Compensation, Discussion and Analysis—2025 Compensation Decisions and Performance” section under the heading “Annual Cash Incentives”, a portion of each NEO's 2025 target total annual incentive opportunity was replaced with an award of Rollover TSR PSUs. The amounts in this column reflect the remaining one-third of our NEOs' (other than Mr. Ball's) 2025 target total annual incentive opportunity that was structured as a cash incentive payment determined according to performance. (4)The amounts disclosed in this column represent the portion of interest accrued (but not currently paid or payable) on deferred compensation that is considered above-market under SEC rules. In 2023 and 2024, the portion of interest accrued (but not currently paid or payable) on deferred compensation was not considered above market. Additional information regarding this plan is below under “2025 Non-qualified Deferred Compensation.” (5)Includes all other compensation, the components of which for 2025 are described in the table immediately below.

  83. Summary Compensation Table

    | 30 | 2026 Proxy Statement |

  84. EXECUTIVE AND DIRECTOR COMPENSATION

    EXECUTIVE AND DIRECTOR COMPENSATION

  85. EXECUTIVE AND DIRECTOR COMPENSATION

    EXECUTIVE AND DIRECTOR COMPENSATION

  86. 2025 Grants of Plan Based Awards

    2025 Grants of Plan Based Awards As further described in the “Compensation Discussion and Analysis” section above, the following table shows the details concerning the potential amounts payable to Messrs. Ball, Sullivan and Lucas and Mses. Smith and Apostolou for performance during 2025 under our annual incentive plan. The actual annual incentive amounts earned and paid to each NEO are included in the “Summary Compensation Table” above. The table below also reflects PSUs (including Rollover TSR PSUs) and RSUs granted to each NEO during 2025 under our LTIP, where applicable.

  87. 2025 Grants of Plan Based Awards

    | | | | Date Management Development and Compensation Committee Took Action | Estimated Possible Future Payouts Under Non-Equity Incentive Plan Awards(2) | | | Estimated Future Payouts Under Equity Incentive Plan Awards(3) (4) | | | All Other Stock Awards: Number of Shares of Stock or | Grant Date Fair Value of Stock and Option | | Name | Form of Award(1) | Grant Date | to Grant Award | Threshold ($) | Target ($) | Maximum ($) | Threshold (#) | Target (#) | Maximum (#) | Units(4) (5) (#) | Awards(6) ($) | | Leroy M. Ball | Annual Cash Incentive Award | | | — | — | — | | | | | | | | PSU Award | 1/3/2025 | 12/4/2024 | | | | 31,218 | 124,871 | 249,742 | | $4,231,780 | | | RSU Award | 1/3/2025 | 12/4/2024 | | | | | | | 28,816 | 914,044 | | Jimmi Sue Smith | Annual Cash Incentive Award | | | 55,000 | 110,000 | 220,000 | | | | | | | | PSU Award | 1/3/2025 | 12/4/2024 | | | | 3,434 | 13,737 | 27,474 | | $462,251 | | | RSU Award | 1/3/2025 | 12/4/2024 | | | | | | | 11,272 | 357,548 | | James A. Sullivan | Annual Cash Incentive Award | | | 108,334 | 216,667 | 433,334 | | | | | | | | PSU Award | 1/3/2025 | 12/4/2024 | | | | 9,539 | 38,155 | 76,310 | | $1,285,367 | | | RSU Award | 1/3/2025 | 12/4/2024 | | | | | | | 23,052 | 731,209 | | Stephanie L. Apostolou | Annual Cash Incentive Award | | | 59,375 | 118,750 | 237,500 | | | | | | | | PSU Award | 1/3/2025 | 12/4/2024 | | | | 3,904 | 15,615 | 31,230 | | $524,563 | | | RSU Award | 1/3/2025 | 12/4/2024 | | | | | | | 13,628 | 432,280 | | Stephen G. Lucas | Annual Cash Incentive Award | | | 30,030 | 60,060 | 120,120 | | | | | | | | PSU Award | 1/3/2025 | 12/4/2024 | | | | 2,289 | 9,154 | 18,308 | | $306,168 | | | RSU Award | 1/3/2025 | 12/4/2024 | | | | | | | 9,232 | 292,839 |

  88. 2025 Grants of Plan Based Awards

    (1)The material terms of the awards reflected in this column are provided in the “Compensation, Discussion and Analysis—2025 Compensation Decisions and Performance” section under the headings “Annual Cash Incentives” and “Long-Term Equity Incentives.” The equity incentive plan awards were granted under our LTIP. (2)The amounts shown in these columns represent the threshold, target and maximum possible payouts of annual performance-based cash bonuses for NEOs (other than Mr. Ball) based on the applicable NEO’s salary as of January 1, 2025. Mr. Ball did not receive an annual performance-based cash bonus award in 2025. For Mr. Sullivan, the target payout was 33 percent of salary. For Mses. Smith and Apostolou, the target payout was 25 percent of salary. For Mr. Lucas, the target payout was 17 percent of salary. Threshold performance would yield a payout of 50 percent of target and maximum performance would yield a payout of 200 percent of target. Amounts earned and paid to each NEO under our annual incentive plan are reflected in the “Non-Equity Incentive Plan Compensation” column of the Summary Compensation Table. (3)The amounts shown in these columns represent the threshold, target and maximum possible payouts under our TSR PSUs and EBITDA PSUs granted in 2025. Threshold performance would yield a payout of 25 percent of target for both EBITDA PSUs and TSR PSUs and maximum performance would yield a payout of 200 percent of target for both EBITDA PSUs and TSR PSUs. (4)Unvested RSUs and PSUs granted under our LTIP are entitled to DEUs. (5)The RSU awards generally will vest in equal annual installments over four years on the anniversary of the January 3, 2025 grant date. (6)The amounts shown in this column represent the aggregate grant date fair value of PSUs and RSUs granted to our NEOs in 2025. See Footnote 2 to the Summary Compensation Table above, computed in accordance with FASB ASC Topic 718.

  89. 2025 Grants of Plan Based Awards

    | 32 | 2026 Proxy Statement |

  90. EXECUTIVE AND DIRECTOR COMPENSATION

    EXECUTIVE AND DIRECTOR COMPENSATION

  91. Outstanding Equity Awards at Fiscal Year-End

    Outstanding Equity Awards at Fiscal Year-End The table below provides information concerning unvested RSUs, PSUs and unexercised options held by each NEO at December 31, 2025.

  92. Outstanding Equity Awards at Fiscal Year-End

    | | | Option Awards | | | | Stock Awards | | | | | Name | Grant Date | Number of Securities Underlying Unexercised Options Exercisable (#) | Number of Securities Underlying Unexercised Options Unexercisable(1) (#) | Option Exercise Price($) | Option Expiration Date | Number of Shares or Units of Stock That Have Not Vested(2)(#) | Market Value of Shares or Units of Stock That Have Not Vested(3)($) | Equity Incentive Plan Awards: Number of Unearned Shares, Units or Other Rights That Have Not Vested(4)(#) | Equity Incentive Plan Awards: Market or Payout Value of Unearned Shares, Units or Other Rights That Have Not Vested(3)($) | | Leroy M. Ball | 3/1/2016 | 60,728 | | $18.11 | 3/1/2026 | | | | | | | 3/3/2017 | 33,519 | | 44.10 | 3/3/2027 | | | | | | | 3/2/2018 | 41,123 | | 41.60 | 3/2/2028 | | | | | | | 3/6/2019 | 61,178 | | 26.63 | 3/6/2029 | | | | | | | 3/3/2020 | 92,180 | | 19.63 | 3/3/2030 | | | | | | | 1/4/2021 | 49,272 | | 29.84 | 1/4/2031 | | | | | | | 1/4/2022 | 39,885 | 13,295 | 32.19 | 1/4/2032 | | | | | | | | | | | | 181,490 | $4,914,749 | 82,098 | $2,223,214 | | Jimmi Sue Smith | 1/4/2022 | 4,998 | 1,666 | $32.19 | 1/4/2032 | | | | | | | | | | | | 31,339 | $848,660 | 8,701 | $235,623 | | James A. Sullivan | 1/4/2021 | 4,750 | | $29.84 | 1/4/2031 | | | | | | | 1/4/2022 | 3,662 | 3,662 | 32.19 | 1/4/2032 | | | | | | | | | | | | 75,451 | $2,043,213 | 24,575 | $665,491 | | Stephanie L. Apostolou | 1/4/2022 | 4,401 | 1,467 | $32.19 | 1/4/2032 | | | | | | | | | | | | 33,145 | $897,567 | 9,586 | $259,589 | | Stephen G. Lucas | | | | | | 23,053 | $624,275 | 5,774 | $156,360 |

  93. Outstanding Equity Awards at Fiscal Year-End

    (1)Options granted on January 4, 2022 will vest in annual installments of 25 percent over four years beginning on the first anniversary of the grant date. (2)The amounts shown in this column reflect the aggregate number of unvested RSUs awarded in 2022, 2023, 2024 and 2025, and related DEUs, if any. The RSUs (and related DEUs) are scheduled to vest in annual installments of 25 percent over four years beginning on the first anniversary of the grant date for the awards granted in 2022 and 2025 and in annual installments of one-third over three years beginning on the first anniversary of the grant date for the awards granted in 2023 and 2024, as summarized below. Included in this column are the earned portion (and related DEUs) of: (i) 2023-2025 TSR PSU awards, which were earned for performance through 2025 at 150.0 percent of target and vested on January 5, 2026; (ii) 2023-2025 EBITDA PSU awards, which were earned for performance through 2025 at 116.1 percent of target and vested on January 5, 2026; and (iii) 2025-2027 TSR PSU awards, which were earned for performance through 2025 at 38.6 percent of target and will vest on January 5, 2028.

  94. Outstanding Equity Awards at Fiscal Year-End

    | KOPPERS HOLDINGS INC. | 33 |

  95. EXECUTIVE AND DIRECTOR COMPENSATION

    EXECUTIVE AND DIRECTOR COMPENSATION

  96. EXECUTIVE AND DIRECTOR COMPENSATION

    | Name | Grant Date | # of Unvested Shares | Vesting Date | | Leroy M. Ball | 1/4/2022 | 4,994 | 1/5/2026 | | | 1/4/2023 | 7,354 | 1/5/2026 | | | 1/4/2023 | 117,439 | 1/5/2026 | | | 1/4/2024 | 5,041 | 1/5/2026 | | | 1/4/2024 | 5,041 | 1/5/2027 | | | 1/3/2025 | 7,282 | 1/5/2026 | | | 1/3/2025 | 7,282 | 1/5/2027 | | | 1/3/2025 | 7,282 | 1/5/2028 | | | 1/3/2025 | 7,282 | 1/5/2029 | | | 1/3/2025 | 12,493 | 1/5/2028 | | Jimmi Sue Smith | 1/4/2022 | 937 | 1/5/2026 | | | 1/4/2023 | 2,210 | 1/5/2026 | | | 1/4/2023 | 12,674 | 1/5/2026 | | | 1/4/2024 | 1,452 | 1/5/2026 | | | 1/4/2024 | 1,452 | 1/5/2027 | | | 1/3/2025 | 2,848 | 1/5/2026 | | | 1/3/2025 | 2,848 | 1/5/2027 | | | 1/3/2025 | 2,848 | 1/5/2028 | | | 1/3/2025 | 2,848 | 1/5/2029 | | | 1/3/2025 | 1,222 | 1/5/2028 | | James A. Sullivan | 1/4/2022 | 2,062 | 1/5/2026 | | | 1/4/2023 | 5,663 | 1/5/2026 | | | 1/4/2023 | 32,465 | 1/5/2026 | | | 1/4/2024 | 4,250 | 1/5/2026 | | | 1/4/2024 | 4,250 | 1/5/2027 | | | 1/3/2025 | 5,825 | 1/5/2026 | | | 1/3/2025 | 5,825 | 1/5/2027 | | | 1/3/2025 | 5,825 | 1/5/2028 | | | 1/3/2025 | 5,825 | 1/5/2029 | | | 1/3/2025 | 3,461 | 1/5/2028 | | Stephanie L. Apostolou | 1/4/2022 | 824 | 1/5/2026 | | | 1/4/2023 | 2,123 | 1/5/2026 | | | 1/4/2023 | 12,170 | 1/5/2026 | | | 1/4/2024 | 1,452 | 1/5/2026 | | | 1/4/2024 | 1,452 | 1/5/2027 | | | 1/3/2025 | 3,444 | 1/5/2026 | | | 1/3/2025 | 3,444 | 1/5/2027 | | | 1/3/2025 | 3,444 | 1/5/2028 | | | 1/3/2025 | 3,444 | 1/5/2029 | | | 1/3/2025 | 1,348 | 1/5/2028 | | Stephen G. Lucas | 1/4/2023 | 1,556 | 1/05/2026 | | | 1/4/2023 | 8,921 | 1/5/2026 | | | 1/4/2024 | 1,258 | 1/5/2026 | | | 1/4/2024 | 1,258 | 1/5/2027 | | | 1/3/2025 | 2,333 | 1/5/2026 | | | 1/3/2025 | 2,333 | 1/5/2027 | | | 1/3/2025 | 2,333 | 1/5/2028 | | | 1/3/2025 | 2,333 | 1/5/2029 | | | 1/3/2025 | 728 | 1/5/2028 |

  97. EXECUTIVE AND DIRECTOR COMPENSATION

    (3)The amounts shown in this column represent the market value of these stock awards (and related DEUs) based on a closing market price of $27.08 per share on December 31, 2025, the last trading day in 2025. (4)The amounts shown in this column reflect the aggregate number of unvested PSUs awarded in 2024 and 2025. All TSR PSU grants (and related DEUs, if any), are scheduled to vest if we achieve a total shareholder return ranking above the 25th percentile as compared to the S&P Small Cap 600 Materials Index during the last two months of the applicable performance period. As of December 31, 2025, the total shareholder return ranked below the 25th percentile for the 2024 outstanding awards and above the 25th percentile for the 2025 outstanding awards. Accordingly, for purposes of determining the amounts shown in this column, we assumed threshold performance with respect to the 2024 TSR PSU awards and target performance with respect to the 2025 TSR PSU awards in accordance with applicable SEC regulations. All EBITDA PSU grants (and related DEUs, if any) are scheduled to vest if we achieve three-year cumulative adjusted EBITDA goals. As of December 31, 2025, we have not met threshold cumulative adjusted EBITDA. Accordingly, for purposes of determining the amounts shown in this column, we assumed threshold performance with respect to the 2024 and 2025 EBITDA PSU

  98. EXECUTIVE AND DIRECTOR COMPENSATION

    | 34 | 2026 Proxy Statement |

  99. EXECUTIVE AND DIRECTOR COMPENSATION

    EXECUTIVE AND DIRECTOR COMPENSATION awards in accordance with applicable SEC regulations. The actual number may be more or less depending on the company’s performance during the applicable performance periods. The number of unvested shares is summarized below.

  100. EXECUTIVE AND DIRECTOR COMPENSATION

    | Name | Grant Date | # of Unvested Shares | Vesting Date | | Leroy M. Ball | 1/4/2024 | 10,083 | 1/5/2027 | | | 1/3/2025 | 72,015 | 1/5/2028 | | Jimmi Sue Smith | 1/4/2024 | 1,271 | 1/5/2027 | | | 1/3/2025 | 7,430 | 1/5/2028 | | James A. Sullivan | 1/4/2024 | 3,720 | 1/5/2027 | | | 1/3/2025 | 20,855 | 1/5/2028 | | Stephanie L. Apostolou | 1/4/2024 | 1,271 | 1/5/2027 | | | 1/3/2025 | 8,315 | 1/5/2028 | | Stephen G. Lucas | 1/4/2024 | 1,101 | 1/5/2027 | | | 1/3/2025 | 4,673 | 1/5/2028 |

  101. 2025 Option Exercises and Stock Vested

    2025 Option Exercises and Stock Vested The table below sets forth information concerning aggregate exercises of stock options and the vesting of a portion of RSUs and PSUs held by the NEOs during 2025.

  102. 2025 Option Exercises and Stock Vested

    | | Option Awards | | Stock Awards | | | Name | Number of Shares Acquired on Exercise | Value Realized on Exercise(1) | Number of Shares Acquired on Vesting | Value Realized on Vesting(2) | | Leroy M. Ball | 6,000 | $78,060 | 73,196 | $2,365,931 | | Jimmi Sue Smith | — | — | 13,557 | 437,451 | | James A. Sullivan | — | — | 30,530 | 985,001 | | Stephanie L. Apostolou | — | — | 12,427 | 400,846 | | Stephen G. Lucas | — | — | 9,234 | 253,145 |

  103. 2025 Option Exercises and Stock Vested

    (1)Value realized is calculated by multiplying the number of exercised options by the difference between the closing price of our common stock on the date of exercise and the exercise price of the stock option. Amounts included do not deduct any taxes paid by the NEOs in connection with such exercises. (2)The amounts in this column represent the number of shares acquired upon the vesting of PSUs and RSUs multiplied by the closing stock price on the applicable vesting date. Amounts included do not deduct any taxes paid by the NEOs in connection with the vesting of the PSUs and RSUs.

  104. 2025 Non-qualified Deferred Compensation

    2025 Non-qualified Deferred Compensation The table below sets forth information as of December 31, 2025 with respect to our Benefit Restoration Plan, a defined contribution plan that provides for the deferral of compensation on a basis that is not tax-qualified. The Benefit Restoration Plan is described in further detail below. None of our NEOs made any contributions or withdrawals during 2025 under the Benefit Restoration Plan.

  105. 2025 Non-qualified Deferred Compensation

    | Name | Registrant Contributions in Last Fiscal Year ($)(1) (2) | Aggregate Earnings in Last Fiscal Year ($)(3) | Aggregate Balance at Last Fiscal Year End ($)(2) (4) | | Leroy M. Ball | $57,796 | $38,075 | $781,125 | | Jimmi Sue Smith | 12,592 | 2,173 | 56,423 | | James A. Sullivan | 30,736 | 12,187 | 266,694 | | Stephanie L. Apostolou | 13,921 | 2,636 | 66,238 | | Stephen G. Lucas | 4,886 | 630 | 18,289 |

  106. 2025 Non-qualified Deferred Compensation

    (1)The amounts shown in this column are reported as compensation in 2025 in the Summary Compensation Table. (2)As described above, the amounts disclosed in these columns include an assumed amount for employer credits made under our Benefit Restoration Plan. Actual employer credits have not yet been made for 2025; however, for purposes of this table, we have assumed that such amounts will be credited for 2025 in accordance with past practice. (3)Amounts reported in this column are reported as compensation in 2025 as Change in Nonqualified Deferred Compensation Earnings in the Summary Compensation Table for each NEO.

  107. 2025 Non-qualified Deferred Compensation

    | KOPPERS HOLDINGS INC. | 35 |

  108. EXECUTIVE AND DIRECTOR COMPENSATION

    EXECUTIVE AND DIRECTOR COMPENSATION (4)The following amounts reported in this column were reported as compensation in the Summary Compensation Table for previous years: $590,485 for Mr. Ball, $33,481 for Ms. Smith, $197,546 for Mr. Sullivan, $46,623 for Ms. Apostolou and $6,467 for Mr. Lucas.

  109. Potential Payments upon Termination or Change in Control

    Potential Payments upon Termination or Change in Control The following information and related table set forth the details of the payments and benefits that would be provided to each NEO in the event that his or her employment is terminated with us for any reason including resignation, termination without cause, retirement, a constructive termination, a change in control or a change in the NEO’s responsibilities.

  110. EXECUTIVE AND DIRECTOR COMPENSATION

    EXECUTIVE AND DIRECTOR COMPENSATION

  111. EXECUTIVE AND DIRECTOR COMPENSATION

    EXECUTIVE AND DIRECTOR COMPENSATION PSUs also provide that if the grantee’s employment terminates by reason of his or her (i) retirement, death or permanent disability for 2023 grants, or (ii) early retirement, death, permanent disability or involuntarily after such grantee has completed at least 30 years of service other than in connection with a termination for misconduct for 2024 and 2025 grants (other than for Rollover TSR PSUs), in each case, on or after the last day of the measurement period but before the vesting date, then the grantee will vest in a number of shares equal to the number of shares (if any) in which he/she would have vested had his or her service continued without interruption through the vesting date. Rollover TSR PSUs provide that, on January 5, 2028, the grantee will vest in a number of shares if the grantee's employment terminates for any reason (including death or permanent disability) prior to January 5, 2028 other than (i) involuntary termination for misconduct; or (ii) voluntarily during the one-year period following the grant date if such termination is not a retirement. In any qualifying voluntary termination (including a retirement) prior to December 31, 2027, the grantee will vest in a number of shares (if any) in which he/she would have been vested on January 5, 2028 had he or she continued in our service through January 5, 2028, multiplied by a fraction, the numerator of which is the number of days of service the grantee completed between the award date and the termination of the grantee's service, and the denominator of which is the total number of days during the period beginning on the award date and ending on January 5, 2028. In the case of any other termination, the grantee will vest in a number of shares (if any) in which he/she would have vested on January 5, 2028 had he or she continued in our service through such date determined according to actual performance during the performance period. In the event of termination of a grantee's service for any reason other than death or permanent disability, vesting is conditioned upon the grantee's continued compliance with restrictive covenants through January 5, 2028, which shall also serve as the issue date for any vested shares. For purposes of the Rollover TSR PSUs, retirement means voluntary termination from service (i) on or after the attainment of age 65, or (ii) on or after the attainment of age 55 with at least 10 years of service. In the event of a change in control, awards to the NEOs may be assumed or otherwise continued in effect or replaced with a cash or equity retention program by the successor company. If this occurs, there will be no automatic accelerated vesting of unvested RSUs, PSUs (including Rollover TSR PSUs) and stock options, regardless of the year in which they were granted. If the NEO is involuntarily terminated (for reasons other than misconduct) within 24 months following the change in control, then any outstanding unvested RSUs, PSUs (including Rollover TSR PSUs) and stock options shall become vested. If the awards to the NEOs are not assumed or otherwise continued in effect or replaced with a cash retention program by the successor company (or if the NEO is involuntarily terminated for reasons other than misconduct within 24 months following the change in control), there will be accelerated vesting of unvested RSUs, PSUs (including Rollover TSR PSUs) and stock options. For PSUs granted in 2023, if the change in control occurs within the first eighteen months of the measurement period, this accelerated vesting would be for a number of shares equal to the number of shares that would have been earned if the performance objective at the end of the measurement period was at the target level (less any shares in which the grantee is at the time vested), and if the change in control occurs on or after the first day of the nineteenth month of the measurement period, this accelerated vesting would be for a number of shares equal to the number of shares that would have been earned pursuant to the performance objective (pro-rated through the date of the change in control if it occurs prior to the end of the measurement period) based on our actual performance through the earlier of the effective date of the change in control or the end of the measurement period. For EBITDA PSUs granted in 2024 and 2025, this accelerated vesting would be for a number of shares based upon whether our compound annual growth rate of adjusted EBITDA meets certain performance thresholds as of the date of the change in control rather than on the basis of three-year cumulative adjusted EBITDA. For TSR PSUs granted in 2024 and 2025 (including Rollover TSR PSUs), this accelerated vesting would be for a number of shares equal to the number of shares that have been earned pursuant to the performance objective (with such performance objective being pro-rated through the date of the change in control if it occurs prior to the end of the measurement period) based on our actual performance through the earlier of the effective date of the change in control or the end of the measurement period.

  112. EXECUTIVE AND DIRECTOR COMPENSATION

    EXECUTIVE AND DIRECTOR COMPENSATION •The estimated amounts included in the table only represent additional amounts that would be payable on the specific termination event. •The amounts estimated in connection with a termination related to a change in control in the table include the amount an NEO is entitled to receive under the LTIP if the awards are assumed or otherwise continued in effect or replaced with a cash retention program by the successor company followed by a qualifying termination. The amounts shown relating to TSR PSU awards and 2024 EBITDA PSU awards represent the value of these awards based on the actual performance through the effective date of the change in control on a pro-rated basis. The amounts shown relating to 2025 EBITDA PSU awards represent the value of these awards based on our compound annual growth rate of adjusted EBITDA as of the date of the change in control. In the event of a change in control in which the awards are not assumed or otherwise continued in effect or replaced with an equity award or cash retention program by the successor company, each NEO would be entitled to the equity award vesting acceleration set forth below under a Qualifying Termination Following a Change in Control.

  113. EXECUTIVE AND DIRECTOR COMPENSATION

    | Named Executive Officer | Termination Due to Death or Disability(1) | Termination Due to Retirement(1) | Qualifying Termination Following a Change in Control | Termination Without Cause Not Related to Change in Control(3) | | Leroy M. Ball | | | | | | Bonus | $— | $— | $1,082,578 | $— | | Cash severance | — | — | 1,950,000 | 281,250 | | Equity vesting | 4,949,494 | 4,216,164 | 5,952,361 | 405,965 | | Health and welfare | — | — | 45,514 | — | | Cutback(2) | — | — | — | — | | | $4,949,494 | $4,216,164 | $8,941,138 | $687,215 | | Jimmi Sue Smith(4) | | | | | | Bonus | $58,520 | $58,520 | $255,750 | $— | | Cash severance | — | — | 880,000 | 42,310 | | Equity vesting | 703,899 | — | 966,888 | 80,999 | | Health and welfare | — | — | 55,346 | — | | Cutback(2) | — | — | 106,799 | — | | | $762,419 | $58,520 | $2,264,783 | $123,309 | | James A. Sullivan | | | | | | Bonus | $115,267 | $115,267 | $623,650 | $— | | Cash severance | — | — | 1,300,000 | 150,000 | | Equity vesting | 1,761,928 | 1,498,278 | 2,382,939 | 159,526 | | Health and welfare | — | — | 68,092 | — | | Cutback(2) | — | — | — | — | | | $1,877,195 | $1,613,545 | $4,374,681 | $309,526 | | Stephanie L. Apostolou | | | | | | Bonus | $63,175 | $63,175 | $250,188 | $— | | Cash severance | — | — | 950,000 | 127,890 | | Equity vesting | 716,789 | — | 1,022,662 | 87,444 | | Health and welfare | — | — | 10,622 | — | | Cutback(2) | — | — | 15,789 | — | | | $779,964 | $63,175 | $2,249,261 | $215,334 | | Stephen G. Lucas | | | | | | Bonus | $31,952 | $31,952 | $135,492 | $— | | Cash severance | — | — | 720,720 | 20,790 | | Equity vesting | 490,906 | — | 708,815 | 44,210 | | Health and welfare | — | — | 22,044 | — | | Cutback(2) | — | — | — | — | | | $522,858 | $31,952 | $1,587,071 | $65,000 |

  114. EXECUTIVE AND DIRECTOR COMPENSATION

    (1)In the event of termination due to disability or retirement, the executive will receive the pro-rata share of the bonus to which he or she would have otherwise been entitled at year-end subject to the discretion of the CEO (as approved by the management development and compensation committee and the board) in accordance with the company’s annual incentive plan. (2)As discussed in “Change in Control Agreements,” we do not provide for any tax gross-up payments relating to the excise tax on excess “parachute payments” (as defined in the tax code). If an executive is entitled to receive payments upon a change in control, such payments will be reduced (or “cut back”) by the terms of the applicable change in control agreement so that such payments do not exceed the limitation set forth in Section 280G of the tax code.

  115. EXECUTIVE AND DIRECTOR COMPENSATION

    | KOPPERS HOLDINGS INC. | 39 |

  116. EXECUTIVE AND DIRECTOR COMPENSATION

    EXECUTIVE AND DIRECTOR COMPENSATION (3)Under our broad-based severance plan, salaried employees are entitled to one week of cash severance for each year of service if terminated without cause. (4)As discussed above in the “Compensation, Discussion and Analysis” section under the heading “Transition Agreement with Ms. Smith in 2026”, we entered into the Smith Transition Agreement with Ms. Smith effective March 17, 2026 pursuant to which she will receive payments in connection with her retirement that differ from the quantification set forth in this table. In addition to the above amounts, Messrs. Ball, Sullivan and Lucas and Mses. Smith and Apostolou would also be entitled to a post-retirement benefit under our Benefit Restoration Plan, as described on pages 34 and 35. Please see page 34 for a quantification of the related payments.

  117. Director Compensation

    Director Compensation We have adopted a standard arrangement to compensate each of our non-employee directors. In 2025, each non-employee director received the following:

  118. Director Compensation

    | Director Compensation Program | | | Annual Cash Retainer for Non-Employee Directors | $85,000 | | Supplemental Annual Cash Retainer for Non-Executive Chair | 100,000 | | Supplemental Annual Cash Retainer for Lead Independent Director | 25,000 | | Supplemental Annual Cash Retainer for Audit Committee Chair | 20,000 | | Supplemental Annual Cash Retainer for Management Development and Compensation Committee Chair | 17,500 | | Supplemental Annual Cash Retainer for Nominating and Corporate Governance Committee Chair | 15,000 | | Supplemental Annual Cash Retainer for Sustainability Committee and Strategy and Risk Committee Chair | 12,500 | | Annual Equity Award of RSUs | 125,000 | | Supplemental board meeting attendance fee for meetings in excess of six per year | 1,000 | | Supplemental committee meeting attendance fee for meetings in excess of six per year | 1,000 |

  119. Director Compensation

    We also reimburse directors for their out-of-pocket expenses incident to their service on the board and in connection with attendance at board and committee meetings and the annual meeting of shareholders. The annual equity award, which is in the form of RSUs, is issued to incumbent directors upon the date of our annual meeting. The annual equity award is issued to new non-employee directors upon the date that they are first elected to the board and is prorated for new non-employee directors serving less than twelve months. The actual number of RSUs to be granted to each non-employee director is determined on the grant date and is based upon the closing selling price per share of our common stock at the close of regular hours trading (i.e., before after-hours trading begins) on the NYSE as such price is officially quoted in the composite tape of transactions on the NYSE on the grant date. The annual equity award vests upon the earlier to occur of (a) the date which is 365 days after the grant date or (b) the date of the next annual meeting of the company, provided that, in both cases, the director remains in continuous service as a director of the company during such period. If a director terminates service prior to the vesting of his or her RSUs, the director will receive, on the date of termination of service, a number of shares equal to the number of shares in which the director would have vested at the end of the vesting period had he/she continued in our service through the end of such period multiplied by a fraction, the numerator of which is the number of days of service the director completed between the award date and the termination of the director’s service and the denominator of which is 365. In the event of a change in control, there will be accelerated vesting of unvested annual equity award RSUs. At least every two years, the board reviews and sets the compensation for non-employee directors based, in part, on the recommendation of the management development and compensation committee. Director compensation was reviewed by the board in May 2025 and the following changes were adopted: (1) the supplemental annual cash retainer for the lead independent director was set to $25,000; and (2) the value of the annual equity award of RSUs for all non-employee directors was increased from $110,000 to $125,000. Factors considered include (i) the level of compensation necessary to attract and retain qualified directors; (ii) maintaining director independence; and (iii) providing incentives that encourage directors to act in the interests of shareholders. Pursuant to the terms of our LTIP, the aggregate grant date fair value for accounting purposes of all awards granted to any non-employee director during any single calendar year (excluding awards made at the election of such non- employee director in lieu of all or a portion of annual and committee cash retainers) will not exceed $350,000.

  120. Director Compensation

    | 40 | 2026 Proxy Statement |

  121. EXECUTIVE AND DIRECTOR COMPENSATION

    EXECUTIVE AND DIRECTOR COMPENSATION

  122. 2025 Director Compensation

    2025 Director Compensation The table below provides information concerning the compensation of our non-employee directors for 2025. Mr. Ball did not receive compensation for his service as a director (including as chair of the board of directors) in 2025. Mr. Ball’s compensation for his services as an employee is discussed above.

  123. 2025 Director Compensation

    | Name | Fees Earned or Paid in Cash(1) | Stock Awards(2) | Total | | Stephen R. Tritch | $65,416(3) | $— | $65,416 | | Xudong Feng, Ph.D. | 100,500(4) | 125,000 | 225,500 | | Traci L. Jensen | 88,000(5) | 125,000 | 213,000 | | David L. Motley | 102,000(6) | 125,000 | 227,000 | | Albert J. Neupaver | 116,730(7) | 125,000 | 241,730 | | Laura J. Posadas | 13,166 | 62,832 | 75,998 | | Andrew D. Sandifer | 99,984(8) | 125,000 | 224,984 | | Louis L. Testoni | 37,128(9) | — | 37,128 | | Nishan J. Vartanian | 87,000(10) | 125,000 | 212,000 | | Sonja M. Wilkerson | 105,500(11) | 125,000 | 230,500 |

  124. 2025 Director Compensation

    (1)Each director received a total amount of $85,000 for his or her 2025 annual cash retainer, except for Mr. Tritch, Ms. Posadas and Mr. Testoni who each served for only part of the year ended December 31, 2025. Mr. Tritch and Mr. Testoni, who each retired from the board of directors effective May 8, 2025, each received a total amount of $30,056 for their 2025 annual cash retainer for the period from January 1, 2025 through May 8, 2025. Ms. Posadas, who was elected to the board of directors effective as of November 5, 2025, received a total amount of $13,166 for her 2025 annual cash retainer for the period from November 5, 2025 through December 31, 2025. (2)On May 8, 2025, each incumbent non-management member of the board of directors was granted 4,778 RSUs. On November 5, 2025, Ms. Posadas was granted 2,240 RSUs. The amounts in this column relating to the May 8, 2025 awards represent the grant date fair value of that grant, which is determined by multiplying the shares granted by $26.16 per share, the closing stock price on May 8, 2025. The amount in this column relating to Ms. Posadas' November 5, 2025 award represents the grant date fair value of that grant, which is determined by multiplying the shares granted by $28.05 per share, the closing stock price on November 5, 2025. These award grant date fair values have been determined in accordance with FASB ASC Topic 718 using the assumptions underlying the valuation of equity awards set forth in note 8 of the consolidated financial statements in our Annual Report on Form 10-K for the year ended December 31, 2025. As of December 31, 2025, each incumbent non-management director, except Ms. Posadas, held 4,778 unvested RSUs. (3)Mr. Tritch received an additional $35,360 for serving as chair of the board for the period from January 1, 2025 through May 8, 2025. (4)Dr. Feng received an additional $12,500 for serving as chair of the sustainability committee and an additional $3,000 for supplemental meeting fees. (5)Ms. Jensen received an additional $3,000 for supplemental meeting fees. (6)Mr. Motley received an additional $15,000 for serving as chair of the nominating and corporate governance committee and an additional $2,000 for supplemental meeting fees. (7)Mr. Neupaver received an additional $16,230 for serving as lead independent director for the period from May 8, 2025 through December 31, 2025, an additional $12,500 for serving as chair of the strategy and risk committee and an additional $3,000 for supplemental meeting fees. (8)Mr. Sandifer received an additional $12,984 for serving as chair of the audit committee for the period from May 8, 2025 through December 31, 2025 and an additional $2,000 for supplemental meeting fees. (9)Mr. Testoni received an additional $7,072 for serving as chair of the audit committee for the period from January 1, 2025 through May 8, 2025. (10)Mr. Vartanian received an additional $2,000 for supplemental meeting fees. (11)Ms. Wilkerson received an additional $17,500 for serving as chair of the management development and compensation committee and an additional $3,000 for supplemental meeting fees.

  125. EXECUTIVE AND DIRECTOR COMPENSATION

    EXECUTIVE AND DIRECTOR COMPENSATION member of the board, except in circumstances of death, in which case payment will be made as soon as administratively practicable. Each non-employee director’s account balance will be paid in either a lump sum or in annual installments for up to five years. All payments are made in the form of one share of our common stock for each stock unit credited to the director’s deferred account, except that we may elect to pay any fractional stock units in cash.

  126. 2025 Pay Ratio Disclosure

    2025 Pay Ratio Disclosure As required by applicable SEC rules, we are providing the following information about the relationship of the annual total compensation of our employees and the annual total compensation of Leroy M. Ball, our Chief Executive Officer (our “CEO”). For 2025, our last completed fiscal year: •the annual total compensation of our median employee was $88,286; and •the annual total compensation of our CEO, as reported in the Summary Compensation Table included elsewhere in this proxy statement (adjusted as noted below), was $6,372,338.

  127. EXECUTIVE AND DIRECTOR COMPENSATION

    EXECUTIVE AND DIRECTOR COMPENSATION The CEO pay ratio reported above is a reasonable estimate calculated in a manner consistent with SEC rules based on the methodologies and assumptions described above. SEC rules for identifying the median employee and determining the CEO pay ratio permit companies to employ a wide range of methodologies, estimates and assumptions. As a result, the CEO pay ratios reported by other companies, which may have employed other permitted methodologies or assumptions and which may have a significantly different work force structure from ours, are likely not comparable to our CEO pay ratio.

  128. 2025 Pay Versus Performance Disclosure

    2025 Pay Versus Performance Disclosure

  129. Pay Versus Performance Table

    Pay Versus Performance Table As required by applicable SEC rules, we are providing the following information about the relationship between the compensation actually paid ("CAP") to certain individuals and certain of our financial performance measures. The calculations and analysis below do not necessarily reflect our approach to aligning executive compensation with performance. For further information concerning our pay-for-performance philosophy and how we align NEO compensation with our performance, refer to the Compensation Discussion and Analysis above.

  130. Pay Versus Performance Table

    | | | | Average Summary Compensation Table Total | Average Compensation Actually Paid | Value of Initial Fixed $100 Investment Based On: | | | | | Year | Summary Compensation Table Total for PEO(1) | Compensation Actually Paid to PEO(2) | for Non-PEO Named Executive Officers(3) | to Non-PEO Named Executive Officers(4) | Total Shareholder Return(5) | Peer Group Total Shareholder Return(5) | Net Income(6) (In millions) | Adjusted EBITDA(7) (In millions) | | 2025 | $6,358,244 | $1,080,918 | $1,731,522 | $774,881 | $89.66 | $154.36 | $56.0 | $256.7 | | 2024 | 5,879,522 | (2,999,851) | 1,603,998 | 179,349 | 106.14 | 134.78 | 48.6 | 261.6 | | 2023 | 5,960,553 | 17,568,133 | 1,579,169 | 4,141,388 | 166.69 | 133.42 | 89.8 | 256.4 | | 2022 | 5,770,002 | 2,902,239 | 1,404,909 | 903,710 | 91.17 | 111.20 | 63.2 | 228.1 | | 2021 | 5,196,873 | 3,801,572 | 1,362,868 | 982,152 | 100.45 | 118.41 | 84.9 | 223.5 |

  131. Pay Versus Performance Table

    (1)The amounts shown in this column represent the amount of total compensation reported for Leroy M. Ball, our Chief Executive Officer and Chair of the board of directors, who is considered our Principal Executive Officer under applicable SEC rules (the “PEO”), for each corresponding year in the “Total” column of the Summary Compensation Table above. (2)The amounts shown in this column represent the amount of CAP to Mr. Ball, as computed in accordance with Item 402(v) of Regulation S- K. The amounts do not reflect the actual amount of compensation earned by or paid to Mr. Ball during the applicable year. In accordance with the requirements of Item 402(v) of Regulation S-K, the following adjustments were made to Mr. Ball’s total compensation for each year to determine the CAP:

  132. Pay Versus Performance Table

    | Year | Reported Summary Compensation Table Total for PEO(a) | Less Reported Summary Compensation Table Value of PEO Equity Awards(b) | Plus Adjusted Value of Equity Awards(c) | Compensation Actually Paid to PEO | | 2025 | $6,358,244 | $5,145,824 | $(131,502) | $1,080,918 | | 2024 | 5,879,522 | 3,847,177 | (5,032,196) | (2,999,851) | | 2023 | 5,960,553 | 3,572,221 | 15,179,801 | 17,568,133 | | 2022 | 5,770,002 | 3,745,653 | 877,890 | 2,902,239 | | 2021 | 5,196,873 | 3,099,995 | 1,704,694 | 3,801,572 |

  133. Pay Versus Performance Table

    (a)This column represents the amount of total compensation reported for Mr. Ball for each corresponding year in the “Total” column of the Summary Compensation Table above. (b)This column represents the grant date fair value of equity awards reported in the “Stock Awards” and “Option Awards” columns in the Summary Compensation Table above for the applicable year. (c)This column represents an adjustment to the amounts in the “Stock Awards” and “Option Awards” columns in the Summary Compensation Table for the applicable year (a “Subject Year”). For a Subject Year, the adjusted amount replaces the “Stock Awards” and “Option Awards” columns in the Summary Compensation Table for Mr. Ball to arrive at CAP to Mr. Ball for that Subject Year. The adjusted amount is determined by adding (or subtracting, as applicable) the following for that Subject Year: (i) the year-end fair value of any equity awards granted in the Subject Year that are outstanding and unvested as of the end of the Subject Year; (ii) the amount of change as of the end of the Subject Year (from the end of the prior fiscal year) in the fair value of any awards granted in prior years that are outstanding and unvested as of the end of the Subject Year; (iii) for awards that are granted and vest in the Subject Year, the fair value as of the vesting date; (iv) for awards granted in prior years that vest in the Subject Year, the amount equal to the change as of the vesting date (from the end of the prior fiscal year) in the fair value; (v) for awards granted in prior years that are determined to fail to meet the applicable vesting conditions during the Subject Year, a deduction for the amount equal to the fair value at the end of the prior fiscal year; and (vi) the dollar value of any dividends or other earnings paid on stock or option awards in the Subject Year prior to the vesting date that are not otherwise reflected in the fair value of such award or included in any other component of total compensation for the Subject Year. The valuation assumption for the EBITDA PSUs granted during 2024 is 49 percent of fair value as this represents the probable performance as of December 31, 2025 for the period 2024-2026. The valuation assumption for the EBITDA PSUs granted during 2025 is — percent of fair value as this represents the probable performance as of December 31, 2025 for the period 2025-2027. For stock options, the fair value or change in fair value, as applicable, was determined using a Black-Scholes valuation model. The model references the closing stock price, in addition to the stock option’s strike price, expected life, volatility, expected dividend yield and risk-free rate as of the applicable measurement date. The amounts added or subtracted to determine the adjusted amount are as follows:

  134. Pay Versus Performance Table

    | 44 | 2026 Proxy Statement |

  135. 2025 PAY VERSUS PERFORMANCE DISCLOSURE

    2025 PAY VERSUS PERFORMANCE DISCLOSURE

  136. 2025 PAY VERSUS PERFORMANCE DISCLOSURE

    | Year | Year End Fair Value of Equity Awards Granted in the Year | Year over Year Change in Fair Value of Outstanding and Unvested Equity Awards at FYE Granted in Prior Years | Change in Fair Value of Equity Awards Granted in Prior Years that Vested in the Year | Fair Value at the End of the Prior Year of Equity Awards that Failed to Meet Vesting Conditions in the Year | Adjusted Value of Equity Awards | | 2025 | $2,323,924 | $(2,641,053) | $185,627 | $— | $(131,502) | | 2024 | 1,990,796 | (6,764,522) | (258,470) | — | (5,032,196) | | 2023 | 9,733,619 | 5,183,390 | 262,792 | — | 15,179,801 | | 2022 | 2,339,493 | (949,827) | (388,914) | (122,862) | 877,890 | | 2021 | 2,825,381 | (1,255,454) | 134,767 | — | 1,704,694 |

  137. 2025 PAY VERSUS PERFORMANCE DISCLOSURE

    (3)The amounts shown in this column represent the average of the amounts reported for our NEOs as a group (excluding Mr. Ball) (the "Non- PEO NEOs") in the “Total” column of the Summary Compensation Table in each applicable year. Please refer to the Summary Compensation Table above for the applicable year. The names of each of the Non-PEO NEOs included for purposes of calculating the average amounts in each applicable year are as follows: (i) for 2025 and 2024, Jimmi Sue Smith, James A. Sullivan, Stephanie L. Apostolou and Stephen G. Lucas; (ii) for 2023 and 2022, Jimmi Sue Smith, James A. Sullivan, Stephanie L. Apostolou and Leslie S. Hyde; and (iii) for 2021, Michael J. Zugay, James A. Sullivan, Leslie S. Hyde and Stephanie L. Apostolou. (4)The amounts shown in this column represent the average amount of CAP to the Non-PEO NEOs, as computed in accordance with Item 402(v) of Regulation S-K. The dollar amounts do not reflect the actual average amount of compensation earned by or paid to the Non-PEO NEOs during the applicable year. In accordance with the requirements of Item 402(v) of Regulation S-K, the following adjustments were made to average total compensation for the Non-PEO NEOs for each year to determine the CAP, using the same adjustment methodology described above in Footnote 2(c):

  138. 2025 PAY VERSUS PERFORMANCE DISCLOSURE

    | Year | Average Reported Summary Compensation Table Total for Non-PEO NEOs(a) | Less Average Reported Summary Compensation Table Value of Non-PEO NEO Equity Awards(b) | Less Average Reported Summary Compensation Table Value of Non-PEO NEO Accumulated Pension Benefit(c) | Plus Average Non- PEO NEO Adjusted Value of Equity Awards(d) | Average Compensation Actually Paid to Non-PEO NEOs | | 2025 | $1,731,522 | $1,098,056 | $— | $141,415 | $774,881 | | 2024 | 1,603,998 | 763,366 | — | (661,283) | 179,349 | | 2023 | 1,579,169 | 684,135 | 4,818 | 3,251,172 | 4,141,388 | | 2022 | 1,404,909 | 700,122 | — | 198,923 | 903,710 | | 2021 | 1,362,868 | 635,750 | — | 255,034 | 982,152 |

  139. 2025 PAY VERSUS PERFORMANCE DISCLOSURE

    (a)This column represents the average of the amounts reported for our Non-PEO NEOs in the “Total” column of the Summary Compensation Table above in each applicable year. (b)This column represents the average of the total amounts reported for our Non-PEO NEOs in the “Stock Awards” and “Option Awards” columns in the Summary Compensation Table above in each applicable year. (c)This column represents the average of the change in pension value amounts reported for our Non-PEO NEOs in the “Change in Pension Value and Nonqualified Deferred Compensation Earnings” column in the Summary Compensation Table in each applicable year. (d)This column represents an adjustment to the average of the amounts reported for our Non-PEO NEOs in the “Stock Awards” and “Option Awards” columns in the Summary Compensation Table in each applicable year determined using the same methodology described above in Footnote 2(c). For each year, the adjusted amount replaces the “Stock Awards” and “Option Awards” columns in the Summary Compensation Table for each Non-PEO NEO to arrive at CAP to each Non-PEO NEO for that year, which is then averaged to determine the average CAP to the Non-PEO NEOs for that year. The amounts added or subtracted to determine the adjusted average amount are as follows:

  140. 2025 PAY VERSUS PERFORMANCE DISCLOSURE

    | Year | Average Year End Fair Value of Equity Awards Granted in the Year | Average Year over Year Change in Fair Value of Outstanding and Unvested Equity Awards at FYE Granted in Prior Years | Average Fair Value as of Vesting Date of Equity Awards Granted in the Year and Vested in the Year | Average Change in Fair Value of Equity Awards Granted in Prior Years that Vested in the Year | Average Fair Value at the End of the Prior Year of Equity Awards that Failed to Meet Vesting Conditions in the Year | Adjusted Average Value of Equity Awards | | 2025 | $596,078 | $(468,912) | $— | $14,249 | $— | $141,415 | | 2024 | 472,998 | (1,096,162) | — | (38,119) | — | (661,283) | | 2023 | 2,237,990 | 971,370 | — | 41,812 | — | 3,251,172 | | 2022 | 439,530 | (172,654) | — | (44,192) | (23,761) | 198,923 | | 2021 | 464,793 | (242,260) | 132,024 | 22,112 | (121,635) | 255,034 |

  141. 2025 PAY VERSUS PERFORMANCE DISCLOSURE

    | KOPPERS HOLDINGS INC. | 45 |

  142. 2025 PAY VERSUS PERFORMANCE DISCLOSURE

    2025 PAY VERSUS PERFORMANCE DISCLOSURE (5)The amounts shown in these columns represent an initial $100 investment in each of our common stock and the S&P SmallCap 600 Materials for the cumulative periods from December 31, 2020 through the end of the applicable fiscal year (assuming reinvestment of the pre-tax value of dividends paid during the relevant period). (6)The amounts shown in this column represent the amount of net income reflected in our audited financial statements for the applicable year. (7)The amounts shown in this column represent the amount of our adjusted EBITDA as calculated for performance measurement under our annual incentive plan for the applicable year and to measure performance of the EBITDA PSUs over the relevant three-year measurement period. Adjusted EBITDA, as measured under the annual incentive plan and for the EBITDA PSUs, is defined as earnings before interest, taxes, depreciation and amortization, as adjusted by our management development and compensation committee in its discretion to account for certain items, as set forth on Appendix B hereto.

  143. Analysis of the Information Presented in the Pay Versus Performance Table

    Analysis of the Information Presented in the Pay Versus Performance Table As described in greater detail in the Compensation Discussion and Analysis section above, our executive compensation program reflects a pay-for-performance philosophy. We generally seek to incentivize long-term performance, and therefore we do not specifically align our performance measures with CAP (as computed in accordance with Item 402(v) of Regulation S-K) for a particular year. In accordance with Item 402(v) of Regulation S-K, we are providing the following descriptions of the relationships between information presented in the Pay Versus Performance table.

  144. 2025 PAY VERSUS PERFORMANCE DISCLOSURE

    2025 PAY VERSUS PERFORMANCE DISCLOSURE