EXHIBIT 11 CANTEL INDUSTRIES, INC. COMPUTATION OF EARNINGS PER SHARE Three Months Ended Six Months Ended January 31, January 31, 1998 1997 1998 1997 --------- --------- --------- --------- BASIC Weighted average number of shares outstanding 4,166,322 4,071,804 4,166,322 3,981,803 --------- --------- --------- --------- --------- --------- --------- --------- Net income $ 488,000 $ 442,000 $ 781,000 $ 664,000 --------- --------- --------- --------- --------- --------- --------- --------- Earnings per common share $ 0.12 $ 0.11 $ 0.19 $ 0.17 ------ ------ ------ ------ ------ ------ ------ ------ DILUTED Weighted average number of shares outstanding 4,166,322 4,071,804 4,166,322 3,981,803 Dilutive effect of options and warrants using the treasury stock method and the average market price for the period 229,367 287,042 222,648 358,008 --------- --------- --------- --------- Weighted average number of shares and common stock equivalents 4,395,689 4,358,846 4,388,970 4,339,811 --------- --------- --------- --------- --------- --------- --------- --------- Net income $ 488,000 $ 442,000 $ 781,000 $ 664,000 --------- --------- --------- --------- --------- --------- --------- --------- Earnings per common share $ 0.11 $ 0.10 $ 0.18 $ 0.15 ------ ------ ------ ------ ------ ------ ------ ------