Beer Wine Calculator

Do you know of a calculator to drink? We have to find out how many cases of wine or beer need 4 the wedding?
Figure an average of 4 drinks per drinking age person that drinks. In some ways depends on the crowd, the amount of time and what they are serving. There really is no formula, but we had 102 people and went through 35 bottles of wine, champagne and some of the 15 barrels. There was a cocktail hour and about 4 hours of drinking time.
DRINKsmart – Blood Alcohol Content Reader iPhone App