EXHIBIT 11 BANK OF BOSTON CORPORATION Computation of Earnings Per Common Share Quarters Ended Six Months Ended June 30 June 30 EARNINGS (in millions) 1996 1995 1996 1995 -------- ---- ---- ---- ---- 1. Net income $ 178 $ 133 $ 295 $ 259 2. Less: Preferred dividends 9 9 19 19 ------- ------- ------- ------- 3. Net income applicable to primary and fully diluted earnings per common share $ 169 $ 124 276 $ 240 ======= ======= ======= ======= SHARES (in thousands) ------ 4. Weighted average number of common shares outstanding 109,725 111,369 110,380 109,335 5. Incremental shares from assumed exercise of dilutive stock options as of the beginning of the period using the treasury stock method 1,528 1,564 1,684 1,605 6. Incremental shares from assumed conversion of debentures at date of issuance 1,778 ------- ------- ------- ------- 7. Adjusted number of common shares 111,253 112,933 112,064 112,718 ======= ======= ======= ======= PER SHARE CALCULATION --------------------- 8. Primary net income per common share $ 1.54 $ 1.11 $ 2.50 $ 2.19 (Item 3/Item 4) 9. Fully diluted net income per common share $ 1.52 $ 1.10 $ 2.46 $ 2.14 (Item 3/Item 7)