For 20 people, order 8 large pizzas. That assumes 14-inch pies cut into 8 slices and about 3 slices per guest, which gives you 64 slices for the table. If you're ordering late, we're open until 3 AM, 365 days a year, holidays included, so the answer works at 9 PM or at 2 AM. Below you'll find the quick math, how to adjust it for hungry or light eaters, and what to do for 30 or 50 guests.
TL;DR
- Plan on 8 large pizzas (14-inch, 8 slices each) for 20 people when pizza is the main meal.
- The rule behind it: guests times 3/8 equals pizzas. Round up.
- Hungry crowd? Plan 4 slices each and order about 10. Light eaters or lots of sides? 5 or 6 can do.
- For 30 people order about 12 pizzas, and for 50 people about 19.
- Order direct at zioals.com or in the Zio Al's app and take 15% off your first app order.
Table of Contents
- The short answer: 8 large pizzas
- Why 3 slices per person is the standard
- Adjust the number for your crowd
- Crust, toppings and sides change the math
- Pizza size matters more than pizza count
- Mixing toppings for 20 guests
- What about 30 or 50 people?
- We think the best plan is a simple one
- Order for your group at Zio Al's
- Planning the rest of the party
- A quick checklist before you order
- FAQ
- Sources
The short answer: 8 large pizzas
Eight is the number most pizza guides land on for a group of 20. One Chowhound guide recommends 8 typical large pizzas, assuming 14-inch pies with 8 slices and about 3 slices per guest. That's 64 slices for 20 people, a little over 3 each. A Tasting Table guide from 2026 gets to the same place with a shortcut: multiply your guest count by 3/8.
Try it yourself:
- Take your guest count: 20.
- Multiply by 3: 60 slices needed.
- Divide by 8 slices per pie: 7.5 pizzas.
- Round up: 8 pizzas.
The rounding matters. Running out of pizza at a party is a bad feeling, and a few leftover slices are not. Cold pizza for breakfast is a perk, not a problem.
Why 3 slices per person is the standard
Three slices isn't a random guess. USDA's What We Eat in America data brief looked at nationally representative data from 2017 to March 2020, before the pandemic. It found that males averaged 4 slices and females 3 slices when they ate pizza. Its reference slice is about one-sixth of a 14-inch regular-crust restaurant cheese pizza, so it's a slightly bigger slice than the 1/8 cut most large pies get.
The same brief found that children ages 2 to 5 ate less pizza than those ages 6 to 19. So a mixed group of adults and little kids lands near 3 slices on average, and a room full of teenagers does not.
So 3 slices is the midpoint. Chowhound's pizza ordering tips use the same logic: 4 slices per person for especially hungry groups, 2 for lighter eaters such as young children, and 3 as the default.
Adjust the number for your crowd
Here's what 20 guests look like at each appetite level, using 8-slice large pizzas.
| Crowd | Slices per person | Total slices | Large pizzas to order |
|---|---|---|---|
| Light eaters, young kids, heavy sides | 2 | 40 | 5 |
| Typical mixed group, pizza is dinner | 3 | 60 | 8 (7.5 rounded up) |
| Hungry crowd, teens, teams after practice | 4 | 80 | 10 |
Five pizzas feeds a light-appetite crowd on paper. We'd still lean toward 6 if the party runs long, because people graze over hours, not minutes.
Think about who is coming
Adults who came straight from work will eat more than kids who just had cake. A group of college students splitting the bill will usually eat until it's gone. If you know your guests, trust that over any formula.
Think about the time of day
A noon lunch with sides is a different meal from a midnight study session. Late-night eaters tend to show up hungry and stay a while, and we see groups ordering well after the dinner rush, which is exactly why we keep the ovens going until 3 AM. If the party starts after 9 PM and dinner was early, push toward the 4-slice column.
Crust, toppings and sides change the math
Not every slice fills you up the same. Tasting Table's guide to feeding 20 points out that heavily topped pizzas are more filling per slice, and that thin crust is less filling than deep-dish or stuffed crust. It also tells you to weigh group hunger and age, plus sides, drinks, toppings and crust.
Translate that into an order:
- Thin crust: go with the full 8, or add one. People reach for another slice.
- Hand tossed with several toppings: 7 or 8 will usually do. Our guide to hand tossed vs thin crust shows exactly what to ask for if you want crunch or chew.
- Thick or loaded pies: knock one pizza off the count. A few heavy slices go a long way.
If you're baking extra bases at home to round out the spread, these no yeast pizza bases come together fast on a weeknight.
Add sides and take pizzas off
Wings, salads and pasta fill plates. When you order sides, you can order fewer pies. A rough guide for 20 people:
- One tray of wings or a pasta pan plus a big salad: drop 1 to 2 pizzas.
- Two or more substantial sides: drop 2 to 3 pizzas, and go 6 total.
- Only a salad: drop 1.
Our wings come in 10 sauces, and you can get them traditional, boneless or breaded, so a mixed order is easy. For ideas on what to put on the table next to the pies, see our pizza salad pairings.
Pizza size matters more than pizza count
Eight pizzas means nothing if one person's "large" is a 12-inch and another's is 16. The math above assumes a 14-inch pie cut into 8 slices. Before you order, ask the shop what size their large is and how many slices it's cut into. If the slices are different, rebuild the order from slices, not pies.
The quick fix: figure out total slices needed (guests times slices per person), then divide by the slices in the pie you're ordering. Our pizza slice count guide breaks down how many slices come in each size, and the pizza size guide explains small, medium and large so you can order with confidence.
Mixing toppings for 20 guests
Twenty people means twenty opinions. A simple split keeps most of them happy:
- 3 pies of cheese or classic toppings. The safest slices on the table, and the first to go with kids.
- 2 pies of beef pepperoni. Every crowd has pepperoni people.
- 2 pies with veggies or a lighter build. Good for guests who skip meat.
- 1 specialty pie with turkey ham or beef bacon, or whatever you're curious about.
Our whole menu is pork-free: beef pepperoni, turkey ham and beef bacon are the meats, so you don't have to hunt for what a guest can eat. If someone needs zabiha halal, ask for it when you order. It's available upon request, so say so up front and don't leave it for pickup.
Need ideas beyond the classics? Our kitchen tested topping combinations are built to keep the crust crisp.
What about 30 or 50 people?
The same 3/8 rule scales. Here's the table:
| Guests | Slices at 3 each | Large pizzas (8 slices) | If hungry (4 slices) |
|---|---|---|---|
| 10 | 30 | 4 | 5 |
| 20 | 60 | 8 | 10 |
| 30 | 90 | 12 | 15 |
| 50 | 150 | 19 | 25 |
For 30 people, the Tasting Table 3/8 rule gives about 12 pizzas. For 50 people, 50 times 3/8 comes to 18.75, so 19 is the number. The hungry column is simple arithmetic: guests times 4, divided by 8.
A few notes for big orders:
- Larger groups tend to even out. A few people eat 5 slices, a few eat 1, and the average holds near 3.
- At 50 people, a small cushion of one extra pie is cheap insurance.
- Big orders need a plan for staying hot. See our guide on how to keep pizza hot and safe, with the 140°F target and a 30-minute serving window.
We think the best plan is a simple one
Most people overthink pizza math. We make dough fresh in-house every day and build pizzas to order, and after a lot of party orders, our advice is short: use 3 slices per person, round up, and make sure a few pies suit everyone at the table.
Then think about your guests. Hungry crowd or late night? Go to 4 slices. Lots of sides? Order fewer pizzas and more variety. Wings in 10 sauces, pasta and salads all stretch the order without feeling like a compromise.
Keep the menu simple for everyone. Everything we make is pork-free, with beef pepperoni, turkey ham and beef bacon, and zabiha halal is available upon request. For office lunches, parties and group nights, our catering packages take the counting off your plate. And you can order late, because we're open until 3 AM every day of the year.
Zio Al's Team
Order for your group at Zio Al's
Planning a party, office lunch or late-night get-together across Dallas-Fort Worth or Katy? Order pizza, pasta and wings for dine-in, pickup or delivery, or ask about our catering packages for groups. Order direct at zioals.com or through the Zio Al's app, skip third-party delivery app markups, and get 15% off your first app order.
Tell us your head count and whether your crowd is hungry or light, and you'll land on the right number fast.
Planning the rest of the party
Pizza is the center of the meal, but a few small decisions make the night run smoother.
Order early, not at the last minute
For 8 pies or more, give the kitchen time. Orders for groups take longer than a single pie, and you'll want them ready when your guests arrive. Pickup is often easier for a big order: you control the timing and skip the wait for a driver.
Keep it hot
Pizza loses its charm fast. Stack boxes in a warm oven set to a low temperature, and don't leave pies sitting for hours. The 30-minute serving window in our hot pizza guide is a good habit to follow.
Add some fun
If the guests are kids or teens, a little structure goes a long way. Our pizza party ideas cover setups, menus and games that work.
Watching the game
Big game on? Order a little heavier, because people eat more when they're watching and talking. Our game day pizza guide has tips for the DFW crowd, including ordering late.
Check for variety beyond pizza
Some guests want something different. A calzone or stromboli fills a plate in a new way, and our guide to calzone vs stromboli shows how they differ before you order.
A quick checklist before you order
- Count your guests, including kids, and note the age mix.
- Decide slices per person: 2 for light, 3 for typical, 4 for hungry.
- Divide total slices by the slices per pizza, then round up.
- Subtract 1 to 3 pizzas if you're serving wings, pasta or hearty salads.
- Pick toppings: mostly classics, a couple of safe options and one fun pie.
- Tell us about any dietary needs, including zabiha halal upon request.
- Order direct and plan how you'll keep the food warm.
FAQ
How many large pizzas do I need for 20 adults?
Plan on 8 large pizzas if pizza is the main meal. That assumes 14-inch pies with 8 slices, and about 3 slices per person. If your group is hungry, go to 10. If you're also serving wings or pasta, 6 or 7 is usually enough.
How many pizzas for 30 people?
Order about 12 large pizzas. Multiply 30 guests by 3/8 and you get 11.25, which rounds up to 12. Add 2 or 3 more if your guests are teens or hungry after a long day.
How many pizzas for 50 people?
Plan on about 19 large pizzas, since 50 times 3/8 is 18.75. For a very hungry crowd, think closer to 25. For a big group like this, a catering package can simplify the order.
How many pizzas per person should I count?
Think in slices, not pizzas. Three slices per person is the standard, which is 3/8 of a large pizza. USDA's national survey found men averaged 4 slices and women 3 slices at a pizza meal, so use 4 for a hungry group and 2 for young kids.
Do I order fewer pizzas if I have sides?
Yes. Wings, pasta and salads fill people up, so drop one to three pizzas depending on how substantial the sides are. Thin crust is less filling than deep-dish or stuffed crust, so order a little more of it.
Sources
- How Many Pizzas Should You Order To Feed 20 People? (Chowhound)
- The Easiest Way To Figure Out How Much Pizza To Order (Tasting Table)
- How Many Pizzas You'll Need To Feed 20 People (Tasting Table)
- Tips And Hacks For Ordering Pizza Everyone Should Know (Chowhound)
- Pizza Consumption in the U.S., What We Eat in America (USDA)
- 3 Fast No Yeast Pizza Bases for Weeknights