1 EXHIBIT 11.1 STATEMENT RE: COMPUTATION OF PER SHARE INCOME (LOSS) OF ADMINISTAFF, INC. THREE MONTHS SIX MONTHS ENDED JUNE 30, ENDED JUNE 30, ---------------------- -------------------- 1996 1997 1996 1997 ---------------------- -------------------- PRIMARY Average shares outstanding . . . . . . . . . . . . . . . . 10,726 13,449 10,726 12,964 Net effect of dilutive stock options - based on the treasury stock method using average market price . . . 54 154 27 77 Net effect of dilutive stock warrants - based on the treasury stock method using average market price . . . 124 502 62 251 Net effect of dilutive stock warrants - based on the if-converted method . . . . . . . . . . . . . . . . . . * -- * -- Adjustment to give effect to shares optioned to employees within 12 months of the initial filing on Form S-1 of an initial public offering as outstanding as of the beginning of each period presented based on the treasury stock method using the offering price . . . . . . . . . . . . 58 -- 85 -- ----------------------------------------------- Total . . . . . . . . . . . . . . . . . . . . . . . . . . 10,962 14,105 10,900 13,392 =============================================== Net income (loss) . . . . . . . . . . . . . . . . . . . . $ 552 $ 934 ($ 357) $ 927 Add interest from subordinated debt, net of taxes . . . . * -- * -- ----------------------------------------------- Net income (loss) available for common shareholders . . . $ 552 $ 934 ($ 357) $ 927 =============================================== Per share amount . . . . . . . . . . . . . . . . . . . . . $ 0.05 $ 0.07 ($0.03) $ 0.07 =============================================== FULLY DILUTED Average shares outstanding . . . . . . . . . . . . . . . . 10,726 13,449 10,726 12,964 Net effect of dilutive stock options - based on the treasury stock method using ending market price . . . . 54 200 27 100 Net effect of dilutive stock warrants - based on the treasury stock method using ending market price . . . . 124 518 62 259 Net effect of dilutive stock warrants - based on the if-converted method . . . . . . . . . . . . . . . . . . * -- * -- Adjustment to give effect to shares optioned to employees within 12 months of the initial filing on Form S-1 of an initial public offering as outstanding as of the beginning of each period presented based on the treasury stock method using the offering price . . . . . . . . . . . . 58 -- 85 -- ----------------------------------------------- Total . . . . . . . . . . . . . . . . . . . . . . . . . . 10,962 14,167 10,900 13,323 ============================================== Net income (loss) . . . . . . . . . . . . . . . . . . . . $ 552 $ 934 ($ 357) $ 927 Add interest from subordinated debt, net of taxes . . . . * -- * -- ----------------------------------------------- Net income (loss) available for common shareholders . . . $ 552 $ 934 ($ 357) $ 927 =============================================== Per share amount . . . . . . . . . . . . . . . . . . . . . $ 0.05 $ 0.07 ($0.03) $ 0.07 =============================================== * Conversion of the stock warrants and options is not assumed in the computation because their effect is antidilutive.