Basic earnings per share represents the amount of income attributable to each common share outstanding. Diluted earnings per share represents the amount of income attributable to each common share outstanding adjusted for the effects of potentially dilutive common shares. Potentially dilutive common shares include stock options and other stock-based awards. In the periods where the effect would be anti-dilutive, potentially dilutive common shares are excluded from the calculation of diluted earnings per share.

For 2025 and prior years, in periods in which the Company had net income, earnings per share was calculated using the two-class method. This method was required as unvested pre-IPO restricted stock awards had the right to receive non-forfeitable dividends or dividend equivalents if the Company were to declare dividends on its common stock. Pursuant to the two-class method, earnings for each period were allocated on a pro-rata basis to common stockholders and unvested pre-IPO restricted stock awards. Diluted earnings per share was computed using the more dilutive of the (a) two-class method and (b) treasury stock method, as applicable, to the potentially dilutive instruments.

Beginning in 2026, earnings per share is calculated using the treasury stock method. As all pre-IPO restricted stock awards were fully vested in the third quarter of 2025, the use of the two-class method is no longer required. Diluted earnings per share represents the weighted average number of common shares outstanding plus the dilutive effect of potential common shares calculated using the treasury stock method.


	Three Months Ended September 30,				Nine Months Ended September 30,
in thousands of U.S. dollars and share amounts (except per share amounts)	2026		2025		2026		2025
Earnings:
Net income	$	58,391	$	48,400	$	138,623	$	43,102
Less: Allocation to participating securities	—		—		—		3
Net income attributable to Sotera Health Company common shareholders	$	58,391	$	48,400	$	138,623	$	43,099
Weighted Average Common Shares:
Weighted-average common shares outstanding - basic	285,997		284,067		285,557		283,855
Dilutive effect of potential common shares	3,220		2,678		2,714		2,164
Weighted-average common shares outstanding - diluted	289,217		286,745		288,271		286,019
Earnings per Common Share:
Net income per common share attributable to Sotera Health Company common shareholders - basic	$	0.20	$	0.17	$	0.49	$	0.15
Net income per common share attributable to Sotera Health Company common shareholders - diluted	0.20		0.17		0.48		0.15


	Three Months Ended September 30,		Nine Months Ended September 30,
in thousands of share amounts	2026	2025	2026	2025
Stock options	2,956	5,543	3,973	5,570
RSUs	11	1	150	512

Total anti-dilutive securities	2,967	5,544	4,123	6,082