EXHIBIT 11 AIRGAS, INC. EARNINGS PER SHARE CALCULATIONS Three Months Ended June 30, (In thousands, except per share amounts) 2001 2000 -------------------- Weighted Average Shares Outstanding: Basic shares outstanding 67,400 65,100 Stock options - incremental shares 1,000 400 Contingently issuable shares -- 1,800 ------ ------ Diluted shares outstanding 68,400 67,300 ====== ====== Net earnings $13,451 $9,816 ======= ====== Basic earnings per share $ .20 $ .15 ======= ====== Diluted earnings per share $ .20 $ .15 ======= ====== Pro forma amounts assuming the application of the change in accounting principle (adoption of SFAS 142) applied retroactively: Net earnings $13,451 $13,371 ======= ======= Basic earnings per share $ .20 $ .20 ======= ======= Diluted earnings per share $ .20 $ .20 ======= =======