Quantities for any party: appetizers, mains, sides, dessert, and drinks
| Party type | Appetizers (pieces) | Main (oz) | Sides (oz) | Desserts |
|---|---|---|---|---|
| Sit-down dinner | 6 | 8 | 8 | 1 |
| Cocktail party (2 hrs) | 12 + 3 per extra hr | — (apps are the meal) | — | 1.5 |
| BBQ / cookout | 4 | 10 | 10 | 1.5 |
| Graduation / open house | 12 + 3 per extra hr | — (or 6 if meal served) | — (or 6) | 2 |
| Kids' birthday | 3 | 6 | 6 | 2 |
| Holiday gathering | 8 | 8 | 8 | 2 |
| Wedding reception | 10 (cocktail hour) | 7 | 6 | 1 (cake) |
These are the per-adult quantities professional caterers plan from. Kids under 12 eat about half an adult portion. The calculator also adds the drink rule: 2 servings per guest in the first hour, 1 for each hour after.
| Guests (adults) | 8 oz dinner portion | 10 oz BBQ portion | Chicken breast count (6 oz) |
|---|---|---|---|
| 10 | 5.0 lb | 6.3 lb | 14 pieces |
| 20 | 10.0 lb | 12.5 lb | 27 pieces |
| 30 | 15.0 lb | 18.8 lb | 40 pieces |
| 50 | 25.0 lb | 31.3 lb | 67 pieces |
| 100 | 50.0 lb | 62.5 lb | 134 pieces |
Bone-in meats run lighter on yield: a pound of ribs or bone-in chicken delivers roughly half a pound of eaten meat, so double those weights. Shrinkage from cooking also costs about 25% on raw ground beef and brats.
Every party-food mistake is the same mistake: guessing. This calculator replaces the guess with the planning rules caterers actually use — per-person quantities scaled by party length and adjusted for how many guests are children.
Appetizers: 6 pieces per adult when a meal follows, or 12 pieces for a two-hour party where appetizers are the meal, plus 3 pieces for each hour beyond two. Mains: 8 oz of protein per adult for a dinner, 10 oz for a BBQ, 7 oz for a plated reception. Sides: 6-10 oz per adult depending on format. Desserts: 1-2 servings. Drinks: 2 servings in the first hour plus 1 per additional hour. Children under 12 count as half an adult throughout, and the optional cushion adds 10% to everything.
Pick your party type, enter adult and kid counts, and set the length. The 10% cushion is on by default — turn it off if you're buying for a crowd that reliably under-eats, like a late-evening reception after a big lunch. Numbers update as you type. For the alcohol share of the drink count, the wedding alcohol calculator splits servings into beer, wine, and spirits with bottle counts.
Take a graduation open house: 30 adults, 10 kids, three hours. Appetizers at 15 pieces per adult (12 base + 3 for the third hour) with kids at half portions works out to 525 pieces, and the 10% cushion brings the shopping number to 578 pieces. Desserts at 2 per adult: 70 servings, or 77 with the cushion. Drinks: 4 servings per adult over three hours → 140, or 154 servings (about 14.4 gallons) with the cushion.
Now a dinner party for 12 adults, three hours, no kids. Six appetizer pieces each is 72; with the cushion, 80 pieces. The main course is 8 oz × 12 = 96 oz = 6 lb of protein, or 6.6 lb with the cushion — two whole chickens or a 7-lb pork shoulder covers it. Drinks come to 48 servings, 53 with the cushion — about five gallons total. A case of soda (24 cans) plus two gallons of lemonade covers 45 of them, so add a six-pack of seltzer and you're set.
More planning detail, including buffet vs. plated portions and dessert-table math, is in the party food quantities guide.
For a party with a full meal, 6 pieces per person before the meal. For a cocktail party or open house where appetizers ARE the meal, 12 pieces per person for two hours, plus about 3 more pieces for each additional hour. Kids under 12 eat roughly half of an adult portion.
Plan 8 ounces of protein per adult at a sit-down dinner, about 10 ounces for a barbecue where burgers and dogs are the main event, and 7 ounces at a wedding reception with multiple courses. In pounds: 8 ounces per person means one pound feeds two guests.
The standard catering rule is two drinks per guest for the first hour and one drink for each additional hour. At a three-hour party that's four servings per adult, or roughly 160 twelve-ounce servings for 40 guests.
Add about 10 percent. It covers the friend who brings a plus-one, second helpings at the buffet, and the inevitable spill. Running short is the one party mistake you can't fix mid-event, while leftovers keep.
Most graduation parties run three hours with grazing instead of a seated meal, so plan around 15 appetizer pieces per adult and 2 desserts each. For 30 adults and 10 kids, that's roughly 575 pieces and 75 dessert servings with a 10 percent cushion.
Count children under 12 as half an adult for mains, sides, and appetizers. A 10-year-old eats most of a slice of pizza but grazes far less than adults do, and the half-portion rule keeps you from buying a full adult share for every kid.