Exhibit 11 COMPUDYNE CORPORATION COMPUTATION OF EARNINGS PER SHARE PER COMMON AND COMMON EQUIVALENT SHARE Three Months Ended March, 31, 1997 1996 ------- ------ Primary earnings per share Net Earnings from continuing operations $ 120 $ 40 ------ ------ Weighted average common and common equivalent shares 2,848 1,808 Adjustment to options - 28 Adjustment for preferred shares 1,260 1,260 ------ ------ 4,108 3,096 ====== ====== Earnings per share: $ .03 $ .01 ====== ====== Fully diluted earnings per share: Earnings from continuing operations $ 120 $ 40 Adjustment for interest on promissory notes - 10 ------ ------ Net earnings $ 120 $ 50 ====== ====== Weighted average common and common equivalent shares 2,848 3,096 Adjustment for options - 284 Adjustment for preferred shares 1,260 - ------ ------ Fully diluted shares 4,108 3,380 ====== ====== Earnings per share: $ .03 $ .01