Rules to Plan By:
Each adult will consume 1 pound of food total; children, about 1/2 pound.
The more options you have, the less you need of each; decrease the main course portion sizes by 1 to 2 ounces if served on a buffet.
Guests will always eat—and drink—more at night than during the day.
When stocking your bar for a cocktail-centric party, you can either create a few mixed drinks to be served punch-style, allotting 1 gallon for 10 guests, or provide a do-it-yourself array of alcohol and mixers (one 1-liter bottle of alcohol will make up to 22 mixed drinks). For those guests who prefer something lighter, allow for 1 bottle of wine per 8 guests, taking into account white's popularity over red in the summer. Typically, guests will consume 2 drinks in the first hour, and 1 drink every hour after that. Don't forget ice and garnishes. Buy 2 pounds of ice per guest, and a large number of lemons and limes.
Hors D'oeuvres and Appetizers
For a cocktail party with hors d'oeuvres only, assume each guest will eat 4 to 6 bites per hour. Err on the side of variety: more options for smaller bites will ensure well-fed and happy guests. For a cocktail hour preceding a larger meal, 6 bites per person total is a safe estimate. Planning a more intimate dinner party with plated appetizers? 10 ounces of leafy greens for an appetizer salad will feed 10.
For protein-centric parties: plan on serving each adult 6 to 8 ounces of meat or seafood total for their main course. Smaller grill staples like hot dogs, ribs, chicken legs and thighs each run 1 1/2 to 4 ounces each, allowing for more variety on your guests' plates. If you're going with hamburgers, each store-bought patty is about 6 ounces. Consider making homemade smaller patties so guests can mix and match proteins.
No barbecue is complete without a little red, yellow and green. One 20-ounce bottle of fan-favorite ketchup will ensure you have leftovers; for mustard and relish, 10-ounce bottles should be plenty.
Chances are you'll be serving a slew of summery side dishes, so no need to go overboard on portion size for each. For pasta salad, 1 cup per guest will suffice; baked beans, about 1/2 cup. For a group of 10, plan on 7 cups of potato salad and 5 cups coleslaw to feed the crowd.
To serve more variety with heavier grill items, consider an assortment of individual desserts like cookies and watermelon slices, assuming your guests will eat about 2 each. For larger cakelike options, each guest will most likely eat 4 ounces; but to take the guesswork out of baking, pre-slice your cakes or serve messier desserts or ice cream (also 4 ounces per guest) in cups.