EXHIBIT 11 NATIONAL SANITARY SUPPLY COMPANY COMPUTATION OF EARNINGS PER SHARE (a) (UNAUDITED) Three Months Ended Six Months Ended (thousands, except per share data) June 30, June 30, - ---------------------------------- ------------------- ------------------ 1997 1996 1997 1996 ------- ------- ------- ------- Computation of Earnings Per Common and Common Equivalent Share Net Income $ 1,217 $ 1,321 $ 1,842 $ 2,153 ======= ======= ======= ======= Average Number of Shares of Common Stock Outstanding 6,226 6,140 6,204 6,132 Incremental Effect of Unexercised Stock Options 52 86 63 76 ------- ------- ------- ------- Average Number of Shares of Common Stock and Common Stock Equivalents Outstanding 6,278 6,226 6,267 6,208 ======= ======= ======= ======= Earnings per Common and Common Equivalent Share $ 0.19 $ 0.21 $ 0.29 $ 0.35 ======= ======= ======= ======= Computation of Earnings Per Common Share Assuming Full Dilution Net Income $ 1,217 $ 1,321 $ 1,842 $ 2,153 ======= ======= ======= ======= Average Number of Shares of Common Stock Outstanding 6,226 6,140 6,204 6,132 Incremental Effect of Unexercised Stock Options 96 91 85 95 ------- ------- ------- ------- Average Number of Shares of Common Stock Assuming Full Dilution 6,322 6,231 6,289 6,227 ======= ======= ======= ======= Earnings Per Common Share Assuming Full Dilution $ 0.19 $ 0.21 $ 0.29 $ 0.35 ======= ======= ======= ======= (a) This calculation is submitted in accordance with the Securities Exchange Act of 1934. Because the incremental effect of unexercised stock options results in dilution of less than 3%, the per share data presented in the consolidated statement of income excludes the impact of common stock equivalents. E-1 Page 9 of 9