EXHIBIT 11 TRI-COUNTY BANCORP, INC. AND SUBSIDIARIES STATEMENT REGARDING COMPUTATION OF EARNINGS PER SHARE Three Months Ended March 31, 1999 1998 ---------- --------- EARNINGS PER SHARE Net earnings available for common shares and common stock equivalent shares deemed to have a dilutive effect $197,766 $231,792 ======== ======== Basic earnings per share $0.23 $0.20 ===== ===== Diluted earnings per share $0.21 $0.18 ===== ===== Shares used in basic earnings per share computation Weighted average common shares outstanding 878,798 1,167,498 ======= ========= Shares used in diluted earnings per share computation Weighted average common shares outstanding 948,997 1,260,234 Additional potentially dilutive effect of stock options 70,199 92,736 ------ ------ 878,798 1,167,498 ======= =========