EXHIBIT 11 BANK OF BOSTON CORPORATION COMPUTATION OF EARNINGS PER COMMON SHARE (IN MILLIONS, EXCEPT SHARE AND PER SHARE AMOUNTS) QUARTERS ENDED SIX MONTHS ENDED JUNE 30 JUNE 30 --------------- ----------------- 1995 1994 1995 1994 ------- ------- -------- -------- EARNINGS -------- 1. Net income............................. $ 133 $ 95 $ 259 $ 191 2. Less: Preferred dividends.............. 9 10 19 19 ------- ------- -------- -------- 3. Net income applicable to primary earnings per common share............. 124 85 240 172 4. Add: Interest expense on convertible debentures, net of tax................ 1 2 ------- ------- -------- -------- 5. Net income applicable to fully diluted earnings per common share............. $ 124 $ 86 $ 240 $ 174 ======= ======= ======== ======== SHARES (IN THOUSANDS) ------ 6. Weighted average number of common shares outstanding.................... 111,369 106,619 109,335 106,410 7. Incremental shares from assumed exercise of dilutive stock options as of the beginning of the period using the treasury stock method............. 1,564 637 1,605 615 8. Incremental shares from assumed conversion of debentures at date of issuance.............................. 4,030 1,778 4,030 ------- ------- -------- -------- 9. Adjusted number of common shares....... 112,933 111,286 112,718 111,055 ======= ======= ======== ======== PER SHARE CALCULATION --------------------- 10. Primary net income per common share (Item 3 / Item 6)..................... $ 1.11 $ .80 $ 2.19 $ 1.62 11. Fully diluted net income per common share (Item 5 / Item 9)............... $ 1.10 $ .77 $ 2.14 $ 1.56 -------- Note-- Income per common share before extraordinary items, net of tax, on both a primary and fully diluted basis for the six months ended June 30, 1994 is computed by adding $7 million to the numerator.