EXHIBIT 11 BANK OF BOSTON CORPORATION Computation of Earnings Per Common Share Quarters Ended March 31 EARNINGS (in millions) 1996 1995 -------- ---- ---- 1. Net income $ 117 $ 125 2. Less: Preferred dividends 9 9 ------- ------- 3. Net income applicable to primary and fully diluted earnings per common share $ 108 $ 116 ======= ======= SHARES (in thousands) ------ 4. Weighted average number of common shares outstanding 111,034 107,278 5. Incremental shares from assumed exercise of dilutive stock options as of the beginning of the period using the treasury stock method 1,830 970 6. Incremental shares from assumed conversion of debentures at beginning of period 3,572 ------- ------- 7. Adjusted number of common shares 112,864 111,820 ======= ======= PER SHARE CALCULATION --------------------- 8. Primary net income per common share $ .97 $ 1.08 (Item 3/Item 4) 9. Fully diluted net income per common share $ .95 $ 1.04 (Item 3/Item 7)