EXHIBIT 11 TRI-COUNTY BANCORP, INC. AND SUBSIDIARIES STATEMENT REGARDING COMPUTATION OF EARNINGS PER SHARE Three Months Ended Nine Months Ended September 30, September 30, 1998 1997 1998 1997 ---------- ---------- ---------- ---------- EARNINGS PER SHARE Net earnings available for common shares and common stock equivalent shares deemed to have a dilutive effect $246,116 $210,878 $705,104 $682,919 ======== ======== ======== ======== have a dilutive effect Basic earnings per share $0.21 $0.18 $0.60 $0.57 ===== ===== ===== ===== Diluted earnings per share $0.20 $0.17 $0.56 $0.53 ===== ===== ===== ===== Shares used in basic earnings per share computation Weighted average common shares outstanding 1,167,498 1,175,650 1,167,498 1,203,396 ========= ========= ========= ========= Shares used in diluted earnings per share computation Weighted average common shares outstanding 1,251,664 1,256,635 1,258,601 1,277,179 Additional potentially dilutive effect of stock options 84,166 80,985 91,103 73,783 --------- --------- --------- --------- 1,167,498 1,175,650 1,167,498 1,203,396 ========= ========= ========= =========