For weddings, or any large cocktail event, determining how much alcohol and nonalcoholic beverage to purchase can feel like a guessing game. As you estimate how much liquid refreshment you will need, keep in mind the following guidelines on average guest consumption:

• For a liter bottle of alcohol, estimate 20 to 22 drinks.
• For a one-hour cocktail reception before dinner, estimate two drinks per person.
• For a two-hour cocktail party, estimate three drinks per person.
• For a four-hour dinner party, estimate four drinks per person.
• There are approximately five glasses in a bottle of wine.
• A liter of soda has five to seven glasses depending on glass size and ice.
• For a champagne toast, figure on 75 glasses per case.
• For wine with dinner preceded by a cocktail party, you need two or two and a half glasses per person. The proportion of red to white will depend on the season, the wine served, and your guests.