. . . EXHIBIT 11 AIRGAS, INC. AND SUBSIDIARIES EARNINGS PER SHARE CALCULATIONS Years Ended March 31, (In thousands, except per share amounts) 2003 2002 2001 ---------------------------------------- Weighted Average Shares Outstanding: Basic shares outstanding 70,500 68,100 66,000 Stock options and warrants - incremental shares 1,800 1,800 600 Contingently issuable shares -- -- 600 ------- ---------- ------- Diluted shares outstanding 72,300 69,900 67,200 ======= ========== ======= Earnings before the cumulative effect of a change in accounting principle $68,105 $ 48,585 $28,223 Cumulative effect of a change in accounting principle -- (59,000) -- ------- ---------- ------- Net earnings (loss) $68,105 $ (10,415) $28,223 ======= ========== ======= Basic earnings (loss) per share: Earnings per share before the cumulative effect of a change in accounting principle $ .97 $ .71 $ .43 Cumulative effect per share of a change in accounting principle -- (.86) -- ------- ---------- ------- Net earnings (loss) per share $ .97 $ (.15) $ .43 ======= ========== ======= Diluted earnings (loss) per share: Earnings per share before the cumulative effect of a change in accounting principle $ .94 $ .69 $ .42 Cumulative effect per share of a change in accounting principle -- (.84) -- ------- ---------- ------- Net earnings (loss) per share $ .94 $ (.15) $ .42 ======= ========== =======