-22- EMC CORPORATION Exhibit 11.1 Computation of Primary and Fully Diluted Net Income Per Share (unaudited) (Amounts in thousands except share and per share data) Three Months Ended Nine Months Ended ------------------ ----------------- September 30, September 30, September 30, September 30, 1997 1996 1997 1996 ---- ---- ---- ---- Primary - ------- Net income $ 132,622 $ 90,347 $ 372,289 $ 261,946 Add back interest expense on convertible notes 4,205 2,438 9,297 7,316 Less tax effect on interest expense on convertible notes (1,682) (975) (3,719) (2,926) ------------ ------------ ------------ ------------ Net income for purposes of calculating primary net income per share $ 135,145 $ 91,810 $ 377,867 $ 266,336 ============ ============ ============ ============ Weighted average shares outstanding during the period 247,333,328 232,295,208 246,468,084 231,271,815 Common equivalent shares 18,342,474 16,702,332 15,167,452 17,442,159 ------------ ------------ ------------ ------------ Common and common equivalent shares outstanding for purpose of calculating primary net income per share 265,675,802 248,997,540 261,635,536 248,713,974 ============ ============ ============ ============ Primary net income per share (Note 4) $0.51 $0.37 $1.44 $1.07 Fully Diluted - ------------- Net income $ 132,622 $ 90,347 $ 372,289 $ 261,946 Add back interest expense on convertible notes 4,205 2,438 9,297 7,316 Less tax effect on interest expense on convertible notes (1,682) (975) (3,719) (2,926) ------------- ------------ ------------ ------------ Net income for purpose of calculating fully diluted net income per share $ 135,145 $ 91,810 $ 377,867 $ 266,336 ============= ============ ============ ============ Common and common equivalent shares outstanding for purpose of calculating primary net income per share 265,675,802 248,997,540 261,635,536 248,713,974 Incremental shares to reflect full dilution 590,978 797,225 1,162,663 572,536 ------------ ------------ ------------ ------------ Total shares for purpose of calculating fully diluted net income per share 266,266,780 249,794,765 262,798,199 249,286,510 ============= ============ ============ ============ Fully diluted net income per share (Note 4) $0.51 $0.37 $1.44 $1.07