Exactly How Much Champagne (and Other Important Supplies) to Buy for Your Next Party

When it comes to the eats, plan to get 20 percent less food than the number of people attending. So if 40 people responded that they’re coming to your backyard shindig, you’ll be safe if you have enough for 32. If you’re having your party catered, think in trays: Half a tray typically feeds eight people, so realistically you’ll need only four trays of the main course.

Commit to memory: (Guests x 0.8) x (2) = Portions to Buy

Guests need something to snack on while they wait for the grill to heat up. Serving foods that are light and bite-sized is not only an adorable approach but it also makes counting quantities a lot easier. You’ll need an average of six “pieces” per person over a two-hour period. So if the party starts at 3 p.m. and you’re serving dinner at 5 p.m., make sure you have 192 hors d’oeuvres for 40 people. (The 20 percent rule also applies here.)

Commit to memory: (Guests x 0.8) x (6) = Hors d’oeuvres to Pass Around

It’s pretty safe to assume each guest will have four drinks over a span of three hours. Make things easy on yourself and stock coolers with mini bottles of La Marca Prosecco. Each one is equivalent to about two glasses, so since you’re expecting 40 guests, you’ll want to have at least four cases of La Marca on hand (24 mini bottles to a case). To make your party really sparkle, jazz up the prosecco with fruity ice pops for a sweet and summery cocktail.

Commit to memory: (Guests x 4) / (3) = Drinks Needed Per Hour

Think for a minute about how many napkins you personally use at a party. There’s the one you wrap around your drink, the one you use to shield yourself from the juicy burger and the one you use to blot out the barbecue sauce that inevitably drips onto your skirt. On average, people use three napkins, but since there’s always a spill or two, overestimating is a good idea. Four napkins times 40 people is a solid 160.

Commit to memory: Guests x (4) = Napkins to Buy

Forty plates for 40 people, right? Not so much. Since some will be going back for seconds and even thirds (that new burger seasoning will definitely be a hit), you should be prepared with about three disposable plates per person. For larger parties, paper plates are the way to go. For a smaller bunch, consider melamine plates that aren’t so precious you’ll be worried about them breaking. For those, you’ll need two per person: one for dinner and one for dessert.

Commit to memory: Guests x (3) = Disposable Plates and Utensils