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 antidilutive, 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				Six Months Ended
in thousands of U.S. dollars and share amounts (except per share amounts)	June 30, 2026		June 30, 2025		June 30, 2026		June 30, 2025
Earnings (Loss):
Net income (loss)	$	53,643	$	7,962	$	80,232	$	(5,298)
Less: Allocation to participating securities	—		1		—		—
Net income (loss) attributable to Sotera Health Company common shareholders	$	53,643	$	7,961	$	80,232	$	(5,298)
Weighted Average Common Shares:
Weighted-average common shares outstanding - basic	285,773		283,933		285,333		283,747
Dilutive effect of potential common shares(a)	2,375		1,823		2,582		—
Weighted-average common shares outstanding - diluted	288,148		285,756		287,915		283,747
Earnings per Common Share:
Net income (loss) per common share attributable to Sotera Health Company common shareholders - basic	$	0.19	$	0.03	$	0.28	$	(0.02)
Net income (loss) per common share attributable to Sotera Health Company common shareholders - diluted	0.19		0.03		0.28		(0.02)

(a)As the Company reported a net loss for the six months ended June 30, 2025, the calculation of diluted weighted average common shares outstanding is not applicable because the effect of including the potential common shares would be anti-dilutive.


	Three Months Ended		Six Months Ended
in thousands of share amounts	June 30, 2026	June 30, 2025	June 30, 2026	June 30, 2025
Stock options	4,676	5,566	4,672	8,299
RSUs	375	1,473	254	2,669
PSUs	—	—	—	475
Total anti-dilutive securities	5,051	7,039	4,926	11,443