EXHIBIT 11 CANTEL INDUSTRIES, INC. COMPUTATION OF EARNINGS PER SHARE Three Months Ended October 31, 1997 1996 --------- --------- PRIMARY Weighted average number of shares outstanding 4,166,322 3,891,803 Dilutive effect of options and warrants using the treasury stock method and average market price for the period 216,523 429,339 --------- --------- Weighted average number of shares and common stock equivalents 4,382,845 4,321,142 --------- --------- --------- --------- Net income $ 293,000 $ 222,000 --------- --------- --------- --------- Earnings per common share $ 0.07 $ 0.05 --------- --------- --------- --------- FULLY DILUTED Weighted average number of shares outstanding 4,166,322 3,891,803 Dilutive effect of options and warrants using the treasury stock method and the higher of the period-end or average market price for the period 245,400 434,975 --------- --------- Weighted average number of shares and common stock equivalents 4,411,722 4,326,778 --------- --------- --------- --------- Net income $ 293,000 $ 222,000 --------- --------- --------- --------- Earnings per common share $ 0.07 $ 0.05 --------- --------- --------- ---------