How the estimate works
The calculator assumes each drinking guest has about one drink per hour, which is a widely used planning figure. It multiplies your guest count by the share who drink and by the reception length, then splits the total across beer, wine and liquor using the mix you choose. Beer is counted as single bottles or cans, wine at five glasses per 750ml bottle, and spirits at about sixteen cocktails per 750ml bottle.
Tips for stocking the bar
Consider your crowd: a younger group may favor beer and cocktails, while a wine-loving crowd shifts the mix. Guests tend to drink a little more in the first hour, so do not cut it too close. Ask your venue or store about returning unopened bottles, and remember ice, mixers, garnishes and non-alcoholic options for guests who are not drinking.