1 EXHIBIT 11 Proteon, Inc. Computation of Primary and Fully Diluted Loss Per Share (in thousands except per share data) Three months ended Nine months ended September 27, September 28, September 27, September 28, 1997 1996 1997 1996 ------------ ------------ ------------- ------------- Net Loss $(2,894) $(1,763) $(4,340) $(3,967) ======= ======= ======= ======= Weighted average number of common shares outstanding 15,276 15,521 15,312 15,499 Weighted average number of common equivalent shares -- -- -- -- ------- ------- ------- ------- Weighted average number of common and common equivalent shares outstanding used to calculate per share data 15,276 15,521 15,312 15,499 ======= ======= ======= ======= Net (loss) per share: Primary $ (0.19) $ (0.11) $ (0.28) $ (0.26) ======= ======= ======= ======= Fully diluted $ (0.19) $ (0.11) $ (0.28) $ (0.26) ======= ======= ======= =======