EXHIBIT 11.0 KIRBY CORPORATION AND CONSOLIDATED SUBSIDIARIES COMPUTATION OF EARNINGS PER COMMON SHARE Three months ended Six months ended June 30, June 30, ------------------ ----------------- 1999 1998 1999 1998 ------- ------- ------- ------- (in thousands, except per share amounts) Net earnings $ 6,602 $ 6,675 $10,603 $11,715 ====== ====== ====== ====== Basic earnings per share: Weighted average number of common shares outstanding 20,103 21,394 20,230 22,701 ====== ====== ====== ====== Basic earnings per share $ .33 $ .31 $ .52 $ .52 ====== ====== ====== ====== Diluted earnings per share: Weighted average number of common shares outstanding 20,103 21,394 20,230 22,701 Dilutive shares applicable to stock options 117 344 111 320 ------ ------ ------ ------ Shares applicable to diluted earnings 20,220 21,738 20,341 23,021 ====== ====== ====== ====== Diluted earnings per share $ .33 $ .31 $ .52 $ .51 ====== ====== ====== ======