Cameco IPO Presentation Deck

Important Notes/Disclaimers (continued) Cameco Energizing a clean-air world NON-IFRS AND NON-GAAP MEASURES This presentation contain references to certain non-IFRS and non-GAAP financial measures and industry metrics that are used by the Company and WEC, respectively, as indicators of financial performance, such as, (a) with respect to Cameco: "Adjusted EBITDA", and (b) with respect to WEC: "Adjusted EBITDA", "Adjusted EBITDA Margin", "Adjusted free cash flow" and "Adjusted free cash flow margin. Management of the Company believes that these non-IFRS and non-GAAP measures provide useful information to investors regarding the financial condition and results of operations of the Company and WEC, respectively. These measures are not recognized measures under IFRS or U.S. GAAP, as applicable, and do not have a standardized meaning prescribed by IFRS or U.S. GAAP, as applicable, and are therefore unlikely to be comparable to similar measures presented by other companies. Accordingly, these measures should not be considered in isolation nor as a substitute for analysis of the Company's financial information reported under IFRS or WEC's financial information reported under U.S. GAAP. The company believes that these non-IFRS and non-GAAP measures may be useful supplemental information to assist investors, securities analysts and other interested parties in assessing the operational performance of the Company and WEC and their ability to generate cash through operations. Reconciliations of the non-IFRS and non-GAAP measures used by the Company in this presentation can be found in the Additional Information section of this presentation starting on page 21. QUALIFIED PERSONS The technical and scientific information discussed in this presentation with respect to our material properties (McArthur River/Key Lake, Cigar Lake and Inkai) was approved by Scott Bishop, P. Eng., who is an employee of the Company and is a qualified person for the purposes of National Instrument 43-101. We are permitted, under a multijurisdictional disclosure system adopted by the securities regulatory authorities in Canada and the United States of America, to prepare the final base shelf prospectus and any applicable shelf prospectus supplement in accordance with Canadian disclosure requirements. Prospective investors should be aware that such requirements are different from those of the U.S. An investment in the securities of the Company involves risks. Investors should carefully read the "Risk Factors" section of the Corporation's final base shelf prospectus and in the documents incorporated by reference therein including any applicable shelf prospectus supplement. Readers should be aware that the acquisition of the any securities described herein may have tax consequences both in the U.S. and Canada. The final base shelf prospectus delivered herewith or any applicable shelf prospectus supplement may not describe these tax consequences fully. Prospective investors should read the tax discussion in any applicable prospectus shelf supplement and consult their own tax advisors prior to deciding to purchase any of the securities. 3

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