KNIGHT TRANSPORTATION, INC. AND SUBSIDIARIES SCHEDULE OF COMPUTATION OF NET INCOME PER SHARE Three Months Ended March 31, 1998 1997 ---- ---- Basic and diluted: Weighted average common shares outstanding - basic 14,927,136 14,879,718 Effect of stock options (1) 312,965 232,433 ----------- ----------- Weighted average common share and common share equivalents outstanding - diluted 15,240,101 15,112,151 =========== =========== Net Income $ 2,929,335 $ 2,092,005 Net income per common share and common share equivalent Basic $ .20 $ .14 =========== =========== Diluted $ .19 $ .14 =========== =========== Notes: (1) Amount calculated using the treasury stock method. EXHIBIT 11