The Company computed basic net (loss) income attributable to Penumbra, Inc. per share based on the weighted average number of shares of common stock outstanding during the period. The Company computed diluted net (loss) income attributable to Penumbra, Inc. per share based on the weighted average number of shares of common stock outstanding plus potentially dilutive common stock equivalents outstanding during the period. For the purposes of this calculation, stock options, restricted stock, restricted stock units and stock sold through the ESPP are considered common stock equivalents.

A reconciliation of the numerator and denominator used in the calculation of the basic and diluted net (loss) income attributable to Penumbra, Inc. is as follows (in thousands, except share and per share amounts):


	Year Ended December 31,
	2022		2021		2020
Numerator:
Net (loss) income attributable to Penumbra, Inc.	$	(2,002)	$	5,284	$	(15,702)




Denominator:
Weighted average shares used to compute net (loss) income attributable to common stockholders:
Basic	37,841,874		36,764,290		35,766,892
Potential dilutive stock-based options and awards, as calculated using treasury stock method	—		1,116,890		—


Diluted	37,841,874		37,881,180		35,766,892

Net (loss) income attributable to Penumbra, Inc. per share from:
Basic	$	(0.05)	$	0.14	$	(0.44)
Diluted	$	(0.05)	$	0.14	$	(0.44)

For the years ended December 31, 2022 and 2020, outstanding stock-based awards of 2.0 million and 2.0 million shares, respectively, were excluded from the computation of diluted net loss attributable to Penumbra, Inc. per share because their effect would have been anti-dilutive. For the year ended December 31, 2021 outstanding stock-based awards of 15.0 thousand shares were excluded from the computation of diluted net income attributable to Penumbra, Inc. per share because their effect would have been anti-dilutive.