EXHIBIT 11 COMPUTER TASK GROUP, INCORPORATED COMPUTATION OF DILUTED EARNINGS PER SHARE UNDER TREASURY STOCK METHOD SET FORTH IN STATEMENT OF FINANCIAL ACCOUNTING STANDARDS NO. 128 "EARNINGS PER SHARE" (amounts in thousands, except per share data) Year Ended December 31: 2003 2002 2001 2000 1999 - ----------------------- ---- ---- ---- ---- ---- Weighted-average number of shares outstanding during year ................................. 16,663 16,567 16,435 16,187 16,401 Common Stock equivalents - incremental shares under stock option plans ......................... 183 328 -- -- 279 ------- -------- ------- ------- ------- Number of shares on which diluted Income (loss) per share is based ......................... 16,846 16,895 16,435 16,187 16,680 Net income (loss) before cumulative effect of change in accounting principle ........................ $ 2,744 $ 1,362 $(2,202) $(5,661) $16,701 Cumulative effect of change in accounting principle ..................................... -- (37,038) -- -- -- ------- -------- ------- ------- ------- Net income (loss) .......................................... $ 2,744 $(35,676) $(2,202) $(5,661) $16,701 ======= ======== ======= ======= ======= Basic net income (loss) per share Net income (loss) before cumulative effect of change in accounting principle ........................ $ 0.16 $ 0.08 $ (0.13) $ (0.35) $ 1.02 Cumulative effect of change in accounting principle ..................................... -- (2.23) -- -- -- ------- -------- ------- ------- ------- Basic income (loss) per share .............................. $ 0.16 $ (2.15) $ (0.13) $ (0.35) $ 1.02 ======= ======== ======= ======= ======= Diluted net income (loss) per share Net income (loss) before cumulative effect of change in accounting principle ........................ $ 0.16 $ 0.08 $ (0.13) $ (0.35) $ 1.00 Cumulative effect of change in accounting principle ..................................... -- (2.19) -- -- -- ------- -------- ------- ------- ------- Diluted income (loss) per share ............................ $ 0.16 $ (2.11) $ (0.13) $ (0.35) $ 1.00 ======= ======== ======= ======= ======= 22