17. Earnings/(Loss) Per Share

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Basic earnings per share of common stock are computed by dividing net income/(loss) attributable to Plug Power Inc. by the weighted average number of common stock outstanding during the reporting period. Diluted earnings per share of common stock are computed by dividing diluted net income/(loss) attributable to Plug Power Inc. by the diluted weighted average number of common stock outstanding during the period. The diluted shares are computed by using the if-converted method when calculating the potentially dilutive effect, if any, of our convertible senior notes, and the treasury stock method when calculating the potentially dilutive effect, if any, of our outstanding stock option awards, unvested restricted stock and restricted stock unit awards, and common stock warrants.

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The table below details the basic and diluted earnings/(loss) per share attributable to Plug Power Inc. (in thousands, except share and per share amounts):

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In accordance with ASC 260, Earnings Per Share, under the if-converted method, adjustments are made to the calculation numerator and denominator for applicable securities. The numerator adjustment resulting from the dilutive effect of the 6.75% Convertible Senior Notes is comprised of add backs related to interest expense, accretion expense, and the change in fair value of convertible debt instruments for the applicable period.

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The calculation of diluted earnings/(loss) per share requires that each issuance of potential common stock be considered in sequence from most dilutive to least dilutive. For the three months ended September 30, 2026, the 6.75% Convertible Senior Notes were the most dilutive security. The effects of the Company's remaining potentially dilutive

securities were considered to be anti-dilutive and therefore excluded from the calculation of diluted earnings per share (refer to the table below).

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Due to our net loss attributable to Plug Power Inc. for the three months ended September 30, 2025 and the nine months ended September 30, 2026 and 2025, the assumed exercise of outstanding stock option awards, the assumed vesting of outstanding restricted stock and restricted stock unit awards, the assumed conversion of convertible debt instruments, and the assumed exercise of outstanding common stock warrants had an anti-dilutive effect on diluted loss per share for the period and were excluded.

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The following table presents the potential common stock outstanding that were excluded from the computation of diluted earnings/(loss) per share as of the periods presented as including them would have been anti-dilutive:

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