EXHIBIT 11 FIRST BELL BANCORP, INC. COMPUTATION OF PRIMARY AND FULLY DILUTED EARNINGS PER SHARE FOR THE THREE AND NINE MONTHS ENDED SEPTEMBER 30, 1997 (IN THOUSANDS, EXCEPT PER SHARE AMOUNTS) (UNAUDITED) THREE MONTHS NINE MONTHS ENDED ENDED 9/30/97 9/30/97 ------------ ----------- Net income applicable to common stock $1,846 $5,756 ====== ====== PRIMARY EARNINGS PER SHARE Average number of shares of common stock outstanding 6,511 6,876 Add: Common stock equivalents 156 132 Less: Weighted average unearned ESOP shares 607 619 ------ ------ Weighted Average Outstanding Shares 6,060 6,389 ====== ====== Primary earnings per share $ 0.30 $ 0.89 ====== ====== FULLY DILUTED EARNINGS PER SHARE Average number of shares of common stock outstanding 6,511 6,876 Add: Common stock equivalents 173 173 Less: Weighted average unearned ESOP shares 607 619 ------ ------ Weighted average outstanding shares 6,077 6,430 ====== ====== Fully diluted earnings per share $ 0.30 $ 0.89 ====== ======