Basic net income (loss) per share attributable to common stockholders is calculated by dividing the net income (loss) by the weighted-average number of shares of common stock outstanding during the period, less shares subject to repurchase. The diluted net income per share attributable to common stockholders is calculated by giving effect to all potential dilutive common stock equivalents outstanding for the period. The rights, including the liquidation and dividend rights, of the holders of Class A and Class B common stock are identical, except with respect to voting and conversion. Each share of Class A common stock is entitled to one vote per share and each share of Class B common stock is entitled to 20 votes per share. Each share of Class B common stock is convertible into a share of Class A common stock voluntarily at any time by the holder, and automatically upon certain events. The Class A common stock has no conversion rights. As the liquidation and dividend rights are identical for Class A and Class B common stock, the undistributed earnings are allocated on a proportional basis and the resulting net income (loss) per share attributable to common stockholders will, therefore, be the same for both Class A and Class B common stock on an individual or combined basis.


	Three Months Ended September 30,				Nine Months Ended September 30,
(In thousands, except per share data)	2023		2022		2023		2022
Numerator:
Net income (loss) attributable to Class A and Class B common stockholders	$	2,807	$	(18,445)	$	3,950	$	(45,644)


Denominator:
Weighted-average shares in computing net income (loss) per share attributable to Class A and Class B common stockholders, basic and diluted	41,719		39,753		41,190		39,210
Effect of dilutive securities

Dilutive effect of stock options outstanding (1)	3,004		—		3,004		—
RSUs outstanding	2,223		—		2,223		—
Denominator for dilutive net income per common share - weighted-average shares	46,946		39,753		46,417		39,210
Basic income (loss) per common share	$	0.07	$	(0.46)	$	0.10	$	(1.16)
Diluted income (loss) per common share	$	0.06	$	(0.46)	$	0.09	$	(1.16)

(1) The Company had 3.3 million options outstanding as of September 30, 2023. The estimated dilutive effect is calculated as the number of shares expected to be issued upon vesting or exercise, adjusted for the strike price proceeds that are received by the Company and assumed to be used to repurchase shares of Duolingo common stock.

Since the Company was in a net loss position for the three and nine months ended September 30, 2022 there is no difference between the number of shares used to calculate basic and diluted loss per share. The potential shares of common stock that were excluded from the computation of diluted net loss per share attributable to common stockholders for the period presented because including them would have been antidilutive are as follows: