Running out of food can be a host’s worst nightmare—nothing grinds a party to a halt like hungry guests. Although there’s certainly an art to planning a menu, understanding what and how much to serve requires a bit of  mathematical skill as well. While a general rule of thumb is to allot one pound of food per guest, plus beverages and dessert, the following metric can help quantify courses according to party type and what food you plan to serve. 

Hors D’oeuvres: On average, guests consume five hors d’oeuvres per hour for the first two hours, then three per subsequent hour. For a three-hour party consisting of ten guests, therefore, you’ll need to prepare approximately 130 appetizers—with some wiggle room for less if the party’s followed by a meal.

Dips: To calculate volume, add the total weight of the main ingredients and use the one to one-and-half pounds per person rule.

Coffee: Most parties call for coffee, a little or a lot. Serve a nice gourmet coffee and plan for one cup per guest for a cocktail party, and three or more cups when little or no alcohol is being served.

Punch: Estimate ten people to the gallon. That’s a conservative estimate, assuming your guests will drink about three 4-ounce servings during the party.

Cocktails: The amount of cocktails or beers a guest will drink depends on several factors, such as the length of the party, what day of the week it falls on, the beverage’s alcoholic content, and the rowdiness—or conversely, the relaxed nature—of the crowd. Typically, guests consume an average of two drinks per person per hour for the first two hours, and then one drink per hour after that.

When planning your reception, discuss these ratios with your event coordinator to get a clear understanding of how much food will be available to your guests. If in doubt, err on the side of serving more rather than less—don’t let shortage of food be what stops the show!