EXHIBIT 11 AIRGAS, INC. EARNINGS PER SHARE CALCULATIONS Three Months Ended Nine Months Ended December 31, December 31, (In thousands, except per share amounts) 2002 2001 2002 2001 ------------------- ---------------------- Weighted Average Shares Outstanding: Basic shares outstanding 70,600 68,300 70,300 67,900 Stock options and warrants - incremental shares 1,700 2,000 1,800 1,500 -------- -------- --------- --------- Diluted shares outstanding 72,300 70,300 72,100 69,400 ======== ======== ========= ========= Net earnings (loss) $ 16,696 $ 11,845 $ 49,940 $ (19,151) ======== ======== ========= ========= Basic earnings per share $ .24 $ .17 $ .71 $ (.28) ======== ======== ========= ========= Diluted earnings per share $ .23 $ .17 $ .69 $ (.28) ======== ======== ========= =========