Exhibit 11 ITT EDUCATIONAL SERVICES, INC. COMPUTATION OF BASIC AND DILUTED EARNINGS PER SHARE (In thousands, except per share data) THREE MONTHS NINE MONTHS ENDED SEPTEMBER 30, ENDED SEPTEMBER 30, -------------------- --------------------- 1999 1998 1999 1998 -------- ------- ------- ------- Net income $10,050 $2,097 $17,820 $8,765 ------- ------ ------- ------- ------- ------ ------- ------- Shares: Weighted average number of shares of common stock outstanding 24,935 27,000 25,424 27,000 Shares assumed issued less shares assumed purchased on stock options 97 206 162 178 ------- ------ ------- ------- Outstanding shares, for diluted earnings per share calculation 25,032 27,206 25,586 27,178 ------- ------ ------- ------- ------- ------ ------- ------- Earnings per common share: Basic $ 0.40 $ 0.08 $ 0.70 $ 0.32 Diluted $ 0.40 $ 0.08 $ 0.70 $ 0.32