VIALOG CORPORATION CALCULATION OF SHARES USED IN DETERMINING LOSS PER SHARE FOR THE THREE AND SIX MONTHS ENDED JUNE 30, 1997 AND 1998 THREE MONTHS ENDED JUNE 30, SIX MONTHS ENDED JUNE 30, --------------------------- ------------------------- 1997 1998 1997 1998 ---------- ---------- ---------- ---------- BASIC LOSS PER SHARE Weighted average number of common shares outstanding 2,799,300 3,628,072 2,773,300 3,585,370 ========= ========= ========= ========= THREE MONTHS ENDED JUNE 30, SIX MONTHS ENDED JUNE 30, --------------------------- ------------------------- 1997 1998 1997 1998 ---------- ---------- ---------- ---------- DILUTED LOSS PER SHARE Weighted average number of common shares outstanding 2,799,300 3,628,072 2,773,300 3,585,370 Common stock equivalents - - - - --------- --------- --------- --------- Total 2,799,300 3,628,072 2,773,300 3,585,370 ========= ========= ========= =========