Free pizza calculator: how many pizzas for a party

How many pizzas do I need for a party?

Count slices, then count pizzas. Each adult gets 3 slices, each teen 4 and each child 2 when pizza is the whole meal. Multiply by the guests in each group, add the slices up and divide by the slices in a pizza. Round up to a whole pizza. The calculator does that and adjusts for the things below.

Every number is a rule we chose. Nobody measured it and no survey sits behind it, so treat it as a starting point. Each rule is a box under "The rules we use" in the form, and the order changes as you type.

The slice counts give a slice of about the same size at every size: 18.8 square inches for 6 slices on a 12 inch pizza, 19.2 for 8 on a 14 inch, 20.1 for 10 on a 16 inch and 21.2 for 12 on an 18 inch. Restaurants cut their own way, so put in the number yours cuts. Smaller slices mean guests may take more of them.

On this page a large pizza means 14 inch with 8 slices; pick the size your restaurant sells. Rounding up to whole pizzas already leaves spare slices (8 in the sample party), so add a leftover buffer only if you'd rather have extra than run short.

How many slices of pizza per person: kids, teens and adults

Four things move the number: what else is on the table, how hungry the group is, the time of day and how long the event runs. The table shows the slices the calculator plans for one guest of each group.

Other food makes the biggest difference. With a full meal on offer, pizza is one choice among several, so an adult drops to 1.5 slices. Late-night pizza after dinner gets the same half portion because the guests have already eaten. A lunch and a dinner use the same rule; a snack uses 0.6 of it.

Length adds a little. After 2 hours we add 10% for each extra hour, capped at 50%, because a longer event gives guests more chances to take another slice. That is our assumption; set the extra to 0 in the rules panel if your party doesn't work that way.

Pizzas for 10, 25, 50, 100 and 200 guests

This is an example, not a quote. It uses 14 inch pizzas of 8 slices, average appetite, a two hour event, no leftover buffer and no vegan or gluten-free pizzas. The mixed crowd is 60% adults, 10% teens and 30% children, with teens and children rounded down.

Size changes how many pizzas you order. A hundred adults need 300 slices either way, which is 50 pizzas of 12 inch, 38 of 14 inch, 30 of 16 inch or 25 of 18 inch.

How to split toppings without ordering too many

Work out the pizzas you need first, then share them out. The calculator takes four shares (cheese 30, pepperoni 40, vegetarian 20 and meat lover 10 to start) and turns them into whole pizzas that always add up to the order. When a share doesn't land on a whole pizza, the spare one goes to the topping with the biggest fraction left over.

At 4 pizzas the meat lover share rounds to none, because a fourth topping isn't worth a whole pizza yet.

Keep the toppings fewer than the pizzas. Each extra kind is another box to pick through, and a pizza nobody reaches for sits there going cold. Offer the unusual ones on a single pizza until you know guests want a second. Ask the restaurant whether half-and-half is allowed (some do it, some charge for it), because two halves are one pizza.

Allergens and dietary options

Put the number of vegan or dairy-free guests and gluten-free guests in the boxes under the pizzas. The calculator takes their slices out of the main order and orders their pizzas on their own lines. Each guest counts once; if someone is both, count them as vegan and ask the restaurant what it can make for both.

Gluten-free crusts may only be sold in one small size, so a gluten-free pizza has its own slice count. We start it at 6. Change it to what your restaurant sells.

An allergy is not a preference, and this page can't make a pizza safe. Ask the restaurant what is in each pizza you order and how it's made, and write the answer on a card next to the box. Shared ovens, cutters and prep surfaces can carry an ingredient from one pizza to another, so for a guest with celiac disease or a serious allergy, ask the restaurant what it does and let the guest decide. Ask about allergies on the invitation or the RSVP, early enough to order for them.

Label every pizza. A card on each box ("Pepperoni", "Vegetarian", "Vegan, no cheese") saves guests asking and keeps the dietary pizzas from being mixed up with the rest.

Ordering pizza for a large event

When to order

The calculator gives an order-by time from your serving time and the size of the order: 3 hours ahead for under 10 pizzas, 1 day for 10 to 29, and 3 days from 30. Those are our rules, not any restaurant's. A restaurant can only bake so many pizzas an hour, so call and ask how many, and how far ahead it wants a big order, then type its answer into the lead-time rules.

One big order or two

One order is easier: one delivery fee, one tip, one call. For a long event, two orders with the second arriving 30 to 45 minutes after the first keep the pizza hotter and let you adjust the count once you've seen how fast the first batch goes. The cost is a second delivery fee.

Keeping pizza hot

Pizza cools quickly once the lid is open. Boxes hold heat; trays or sheet pans let guests see the choices but cool sooner. Keep boxes closed until serving, and put the spare ones in a warmer or an oven set low if the venue has one. The FDA Food Code sets hot holding at 135°F (57°C), section 3-501.16, and USDA advises throwing out perishable food that has been out more than 2 hours, or 1 hour above 90°F, and keeping hot food at 140°F or above. Your local health department's rules apply, so check them with the venue.

Tables and space

A box for a 14 inch pizza is a little larger than the pizza, so allow about 16 inches a box. A 6 foot table (72 inches) fits 4 in a row with room to open the lids. Stacking two high doubles that, but hides what's inside. At that size, 38 pizzas for 100 adults take 10 six-foot tables of single boxes.

Large, small or a mix

A bigger pizza is often cheaper per slice, but not always, and a mix can beat any one size. The size table under the order shows your count in each size at your prices, with the cheapest mix. At the example prices on this page the sample party's main pizzas cost $169 in 12 inch, $160 in 14, $152 in 16 and $154 in 18, and $145 as 6 pizzas of 18 inch and 1 pizza of 12 inch. Those are examples, not any restaurant's prices.

Catering pizza vs delivery

The same pizza can arrive by delivery or as catering.

For venues and caterers

Pizza from outside is a catering decision, so settle it before the client places an order. Check whether the venue allows outside food at all, who supplies plates, napkins, cutters and serving utensils, where the pizza will be held (oven or warmer space, or a table near the door), and who takes away the empty boxes. Forty pizza boxes are a trash job, and someone should own it.

Then write it down. Put the pizza order on the BEO as its own menu section: pizzas by topping, the dietary pizzas, the delivery time and who receives it. Take the headcount from the final guest count, so a change in the number changes the order. The free catering food calculator covers the rest of the menu, and the free BEO template shows where each part goes.

MyVenueHQ keeps the menu, the guest count and the BEO on one event, so there is one count to change. It's free for one venue and up to 10 events a month on the free plan.

Add this pizza calculator to your website

Venues, planners and wedding blogs can put it on their own site for free. Paste this where you want it; it works in WordPress, Squarespace, Wix and plain HTML. Nothing is tracked about your visitors beyond page views.