STERIS plc

NON-GAAP MEASURES AND RECONCILIATION

Non-GAAP Financial Measures. Non-GAAP financial measures are presented with the intent of providing greater transparency to supplemental financial information used by management and the Board of Directors in their financial analysis and operational decision making. These amounts are disclosed so that the reader has the same financial data that management uses with the belief that it will assist investors and other readers in making comparisons to our historical operating results and analyzing the underlying performance of our operations for the periods presented.

Management and the Board of Directors believe that the presentation of thesenon-GAAP financial measures, when considered along with our GAAP financial measures and the reconciliation to the corresponding GAAP financial measures, provide the reader with a more complete understanding of the factors and trends affecting our business than could be obtained absent this disclosure. It is important for the reader to note that thenon-GAAP financial measures used may be calculated differently from, and therefore may not be comparable to, a similarly-titled measure used by other companies.

The following table presents a financial measure that is considered to be“non-GAAP financial measures” under Securities Exchange Commission rules. Free cash flow is defined by the Company as cash flows from operating activities less purchases of property, plant, equipment and intangibles (capital expenditures) plus proceeds from the sale of property, plant, equipment and intangibles. The Company uses free cash flow as a measure to gauge its ability to fund future debt principal repayments, growth outside of core operations, repurchase shares, and pay cash dividends. STERIS’s calculation of free cash flow may vary from other companies.

Notice of Annual Meeting of Shareholders and 2025 Proxy Statement A-1

SCAN TO STERIS plc VIEW MATERIALS & VOTE w 70 SIR JOHN ROGERSON’S QUAY DUBLIN 2, IRELAND ELECTRONIC If you would like DELIVERY to reduce OF the FUTURE costs incurred PROXY by MATERIALS our company in mailing proxy materials, you can consent to (COMPANY NUMBER 595593) receiving all future proxy statements, proxy cards and annual reports electronically via the Internet. To sign up indicate for electronic that you delivery, agree please to receive follow or access the instructions proxy materials below electronically to vote using in the future Internet years .and, when prompted, VOTE Use the BY Internet INTERNET to - www transmit .proxyvote your voting .com or instructions scan the QR and Barcode for electronic above delivery of information. Please (11:59 Note: p.m. The Eastern cut off Daylight for voting Time by on proxy Tuesday, is 4:59 July a .29, m. 2025) Irish Standard . Have your Time proxy on card Wednesday, in hand when July you 30, access 2025 the web site and follow the instructions to obtain your records and to create an electronic voting instruction form. Use VOTE any BY touch PHONE -tone - 1 telephone -800-690-to 6903 transmit your voting instructions. Please Note: The cut off for voting by on proxy Tuesday, is 4:59 July a.m .29, Irish 2025) Standard . Have your Time proxy on Wednesday, card in hand July when 30, you 2025 call (11:59 and then p.m follow . Eastern the instructions Daylight Time . VOTE Mark, sign BY MAIL and date your proxy card and return it in the postage-paid envelope we have provided or return it to arrive on Tuesday, by 4:59 July a.m 29, . Irish 2025) Standard . Vote Processing, Time on Wednesday, c/o Broadridge, July 51 30, Mercedes 2025 (11:59 Way, Edgewood, p.m. Eastern NY 11717 Daylight . All Time proxy cards received will be forwarded to the Company’s registered office in Ireland electronically. 401(K) Your voting PLAN instructions PARTICIPANTS must be received no later than 4:59 a.m. Irish Standard Time on Saturday, July 26, 2025 (11:59 p.m. Eastern Daylight Time on Friday, July 25, 2025). Use any of the voting methods above to submit your voting instructions. TO VOTE, MARK BLOCKS BELOW IN BLUE OR BLACK INK AS FOLLOWS: V76055-P33101-Z90123 KEEP THIS PORTION FOR YOUR RECORDS THIS PROXY CARD IS VALID ONLY WHEN SIGNED AND DATED. DETACH AND RETURN THIS PORTION ONLY STERIS plc listed The Board below: of Directors recommends you vote “FOR” all of the nominees 1. Election of Directors Nominees: For Against Abstain The Board of Directors recommends you vote “For” all of the following 1a. Dr. Esther M. Alegria ! ! ! proposals. For Against Abstain 2. independent To ratify the appointment registered public of Ernst accounting & Young firm LLP for as the the year Company’s ending 1b. Richard C. Breeden ! ! ! ! ! ! March 31, 2026. 3. statutory To appoint auditor Ernst under & Young Irish Chartered law to hold Accountants office until as the the conclusion Company’s of 1c. Daniel A. Carestio ! ! ! ! ! ! the Company’s next annual general meeting. 4. Committee To authorize of the the Board Board of of Directors Directors to of determine the Company the remuneration or the Audit 1d. Cynthia L. Feldmann ! ! ! ! ! ! auditor of Ernst under & Young Irish Chartered law. Accountants as the Company’s statutory 1e. Christopher S. Holland ! ! ! 5. the To approve, Company’s on named a non-binding executive advisory officers basis, as disclosed the compensation pursuant of to ! ! ! including the disclosure the compensation rules of the U discussion .S. Securities and and analysis Exchange and the Commission, tabular and 1f. Paul E. Martin ! ! ! narrative June 12, 2025 disclosure . contained in the Company’s proxy statement dated 6. To approve a proposal renewing the Board of Directors’ authority to issue 1g. Dr. Nirav R. Shah ! ! ! shares under Irish law. ! ! ! 7. To approve a proposal renewing the Board of Directors’ authority to 1h. Louis A. Shapiro ! ! ! ! ! ! opt-out of statutory pre-emption rights under Irish law. 1i. Dr. Mohsen M. Sohi ! ! ! 8. or To any transact adjournment such other or business postponement as may properly thereof .come before the meeting 1j. Dr. Richard M. Steeves ! ! ! form NOTE: is A signed corporation (or a duly may certified execute copy a form of such of proxy power under or authority) the hand of must a duly be included authorized with officer, the proxy director, form attorney . A shareholder or other person may appoint . Any power more than of attorney one proxy or any to attend other authority on the same under occasion, which this but proxy only if one the proxy shareholder may be votes appointed at the in meeting respect or of adjournment, any one share .the The shareholder’s appointment proxy of a proxy will be shall automatically not preclude revoked a shareholder . A form of from proxy attending shall be and valid voting for any at adjournment the meeting or of at the any meeting adjournment . Please of sign it; exactly however, as name appears above, joint owners should each sign. When signing as attorney, executor, administrator, trustee or guardian, please give full title as such. 912041-013 04Jun25 11:55

YOUR VOTE IS IMPORTANT Regardless of whether you plan to attend the 2025 Annual General Meeting of Shareholders, you can be sure the shares are represented at the meeting by promptly returning your proxy/voting instruction card in the enclosed envelope. Important Notice Regarding the Availability of Proxy Materials for the Annual General Meeting to be held on July 31, 2025: The Notice and Proxy Statement, Fiscal 2025 Annual Report, and Directors’ Report and Consolidated Financial Statements for the Year Ending March 31, 2025 are available at www.proxyvote.com. Sign and date the proxy/voting instruction card on the reverse side.? Please fold and detach proxy card at perforation before mailing.? V76056-P33101-Z90123 STERIS plc SHAREHOLDER’S PROXY AND VOTING INSTRUCTION CARD ANNUAL GENERAL MEETING OF SHAREHOLDERS TO BE HELD ON JULY 31, 2025 This Proxy is solicited by the Board of Directors The shareholder(s) whose signature(s) appear(s) on the reverse side of this proxy card hereby appoint(s) Dr. Mohsen M. Sohi, Daniel A. Carestio, Michael J. Tokich, and J. Adam Zangerle, and each of them, with full power of substitution, as proxies (the “Proxies”), and authorize(s) the Proxies to represent such shareholder(s) and to vote all the ordinary shares in STERIS plc (the “Company”) which the shareholder(s) would be entitled to vote, in the manner directed on the reverse side of this card, on Proposals 1 through 7 and in the discretion of the Proxies with respect to such other business as may properly come before the meeting. The shares represented by this proxy, when executed properly, will be voted in the manner directed. If direction is not given but the card is properly executed, this proxy will be voted “FOR” the election of all nominees under Proposal 1, “FOR” Proposals 2, 3, 4, 5, 6 and 7, and in the discretion of the Proxies with respect to such other business as may properly come before the meeting. SPECIAL INFORMATION for participants in the STERIS Corporation 401(k) Plan (“Plan”): This proxy also provides voting instructions for shares held on the record date for the Annual General Meeting by Vanguard Fiduciary Trust Company (“Vanguard”)*, as trustee of the Plan. If you are a participant in the Plan, this paragraph (and not the paragraph above) applies with respect to voting the Plan shares. By marking and returning this card, you will direct Vanguard (i) how to vote the ordinary shares allocated to the account in the Plan and (ii) how to vote a portion of the ordinary shares allocated to the accounts of other participants in the Plan who have not submitted voting instructions by the voting deadline. If Vanguard receives your properly marked and executed card on or before 4:59 a.m. Irish Standard Time on Saturday, July 26, 2025 (11:59 p.m. Eastern Daylight Time on Friday, July 25, 2025) the (“401(k) Deadline”), Vanguard will vote these shares in the manner directed by you. If direction is not received or not received until after the 401(k) Deadline, Vanguard will vote these Plan shares in the same proportion as the final aggregate vote of the Plan participants who submitted timely votes on the matter. This proxy is solicited on behalf of the Board of Directors pursuant to a separate Notice of 2025 Annual General Meeting and Proxy Statement dated June 12, 2025, receipt of which is hereby acknowledged. OUR BOARD OF DIRECTORS CONSIDERS THAT ALL THE RESOLUTIONS TO BE PUT TO THE MEETING ARE IN THE BEST INTERESTS OF THE COMPANY AND ITS SHAREHOLDERS AS A WHOLE. OUR BOARD OF DIRECTORS UNANIMOUSLY RECOMMENDS THAT YOU VOTE “FOR” EACH RESOLUTION. THIS PROXY AND VOTING INSTRUCTION CARD IS CONTINUED ON THE REVERSE SIDE. 912041-013 04Jun25 11:55 *Vanguard Fiduciary Trust Company, in its capacity as trustee or custodian, has appointed Broadridge as agent to tally the vote.