EXHIBIT 11 PERITUS SOFTWARE SERVICES, INC. COMPUTATION OF NET INCOME (LOSS) PER SHARE AND UNAUDITED PRO FORMA NET LOSS PER SHARE Year ended December 31, ----------------------------------------- 1997 1996 1995 Net income (loss), as reported $(66,910,000) $(4,921,000) $ 55,000 Redeemable stock preference items: Accrual of cumulative dividends on Series A and Series B redeemable convertible preferred stock (675,000) (689,000) - Accretion to redemption value of Series A and Series B redeemable convertible preferred stock - (347,000) - Accretion to redemption value of redeemable common stock right (57,000) (66,000) - ----------------------------------------- Total redeemable stock preference items (732,000) (1,102,000) - ----------------------------------------- Net income (loss) available to common stockholders (67,642,000) (6,023,000) 55,000 ========================================= Basic weighted average common stock outstanding 9,708,000 5,876,000 5,078,000 ========================================= Basic net income (loss) per share $ (6.97) $ (1.02) $ 0.01 ========================================= Diluted weighted average shares outstanding: a. shares attributable to common stock outstanding 9,708,000 5,876,000 5,078,000 b. shares attributable to common stock options and warrants - - 1,378,000 ----------------------------------------- 9,708,000 5,876,000 6,456,000 ========================================= ----------------------------------------- Diluted net income (loss) per share $ (6.97) $ (1.02) $ 0.01 ========================================= - ------------------------------------------------------------------------------------------------------------------------- Net loss $ (66,910,000) $(4,921,000) Unaudited pro forma basic and diluted weighted average shares outstanding: a. shares attributable to common stock outstanding 9,708,000 5,876,000 b. shares attributable to common stock options and warrants - - c. shares attributable to redeemable convertible preferred stock 1,866,000 1,518,000 --------------------------- 11,574,000 7,394,000 =========================== --------------------------- Unaudited pro forma basic and diluted net loss per share $ (5.78) $ (0.67) ===========================