EXHIBIT 11 BOSTON BIOMEDICA, INC. AND SUBSIDIARIES STATEMENT RE COMPUTATION OF INCOME PER SHARE WEIGHTED AVERAGE SHARES QUARTER ENDED SEPT. 30, NINE MONTHS ENDED SEPT. 30, --------------------------------------- ---------------------------------------- 1996 1995 1996 1995 ----------------- ----------------- ------------------- ---------------- Average Common Stock Outstanding 2,690,064 2,547,932 2,628,841 2,557,830 Net effect of dilutive Common Stock Equivalents-based on treasury stock method using average market price 623,044 - 623,044 - Issuance of "Cheap Stock" - 33,295 - 33,295 ----------------- ----------------- ------------------- ---------------- 3,313,108 2,581,227 3,251,885 2,591,125 ================= ================= =================== ================ Net Income $ 162,652 $ (19,361) $ 245,521 $ (55,517) Add: net reduction of interest on debt, less 40% taxes 10,450 - 10,450 - ----------------- ----------------- ------------------- ---------------- Adjusted net income for earnings per share calculation $ 173,102 $ (19,361) $ 255,971 $ (55,517) ================= ================= =================== ================ Income (loss) per share 0.05 (0.01) 0.08 (0.02) ================= ================= =================== ================ 13