How Many Pizzas To Buy Calculator

How Many Pizzas To Buy Calculator

How many pizzas should you buy for 10, 15, 20, 30, 40 or even 50 people (or more)?  If you are planning for a party or trying to feed a large group of people, the Pizza Calculator will help you plan how many pizzas to order so that everyone is happy, and it will even provide topping suggestions.  Considering that the average american consumes 27 pounds of pizza a year (Pizza Market Place), serving pizza is always a popular food choice.

Here are some things to consider when buying pizza for a large number of people (or just skip straight to the calculator at the bottom of this page):

How Many Slices On A Pizza

On average:

There are 6 slices per small (8-10″) pizza
There are 8 slices per 12 inch pizza (medium)
There are 10 slices on a large (14″) pizza
There are 12 slices on an extra-large (16-18″) pizza.

You should confirm the number of slices before ordering because this will vary between pizza providers.

How Much Pizza Do I Need to Order?

Here is a quick breakdown of how many pizzas you would need to order for adult guests.  These are based on ordering medium pizzas which have 8 slices.  You can get a much better value if you order large or extra large pizzas, especially with a coupon.  Use the calculator at the bottom to see how much you would need to order for different sized pizzas.  Plus, you’ll get ordering suggestions for which type of pizzas you might want to order.

How many pizzas for 5 people = 2 medium pizzas
How many pizzas for 10 people= 4 medium pizzas
How many pizzas for 12 people = 5 medium pizzas
How many pizzas for 15 adults = 6 medium pizzas
How many pizzas for 17 people = 7 medium pizzas
How many pizzas for 18 people = 7 medium pizzas
How many pizzas for 20 adults = 8 medium pizzas
How many pizzas for 25 people = 10 medium pizzas
How many pizzas for 30 people = 12 medium pizzas
How many pizzas for 35 people = 14 medium pizzas
How many pizzas for 40 people = 15 medium pizzas
How many pizzas for 45 people = 17 medium pizzas
How many pizzas for 50 people = 19 medium pizzas

Pizza Sizes:

Pizza Sizes In Inches (

  • A Small 10″ inch Pizza has 78.54 square inches (at 6 slices, each slice consists of 13 square inches)
  • A Medium 12″ inch Pizza has 113.10 square inches  (at 8 slices, each slice consists of 14 square inches)
  • A Large 14″ inch Pizza has 153.94 square inches (at 10 slices, each slice consists of 15 square inches)
  • An Extra Large 16″ inch Pizza has 201.06 square inches (at 12 slices, each slice consists of 16 square inches)
  • An 18″ inch Pizza has 254.47 square inches (at 14 slices, each slice consists of 18 square  inches (although these are often cut for 12 slices which would provide a whopping 21 square inches per slice)

How many slices per pizza size at Dominos Pizza and Pizza Hut:

  • A Small 10″ inch Pizza is normally cut into 6 slices and serves 2-3 people
  • A Medium 12″ inch Pizza is normally cut into 8 slices and serves 3-4 people
  • A Large 14″ inch Pizza is normally cut into 8 or 10 slices and serves 3-5 people
  • An Extra Large 16″ inch Pizza is normally cut into 6 or 12 slices and serves 5-6 people
  • An 18″ inch Pizza is normally cut into 6 or 12 slices and serves 6-7 people

Pizza Toppings Ordering Tips

  • Virtually everyone loves cheese pizza, or will eat it if their primary favorite isn’t available. When in doubt, order one-third to one-half of your pizzas as plain cheese or double cheese.
  • Extra cheese is said to keep pizzas warmer longer (increases the pizza “hold” time). Order extra cheese if you need the pizzas to stay warmer just a bit longer.
  • 62% of consumers prefer pizza toppings are meat; with pepperoni comprising 38% and sausage representing 14% of the top preferred meat toppings, and Mushrooms topping at 11% of preferred vegetable toppings.
  • A 14″ large pizza is the most popular size ordered.
  • Specialty pizzas with a large variety/combination of toppings are best ordered if you know your guests’ preferences.  Otherwise they may not be as popular especially if there are picky eaters, leading to a lot of leftovers (AKA “breakfast”).
  • You may need less pizza if you get thicker, specialty crusts or extra (more than 2) toppings.  These tend to be heavier and fill people up faster.

Should You Have A Pizza Bar?

The calculator will recommend some ordering options based on how many pizzas you need.  But instead of stressing over which toppings to order for each pizza, you might consider having a pizza bar.  Pizza bars are popular for weddings, birthdays, and other specialty events.  The obvious exception to offering toppings is if you are offering an artisan pizza bar through a caterer.

For an easy pizza bar, order all your pizzas with just cheese and than offer your guest a variety of toppings so they can create their own masterpiece.  Have a toaster oven set to broil setting ready at the end of the pizza bar table so guests can either heat up their pizza slices with the added ingredients, or they can eat it as is.  As for the extra toppings, you can go all out, or just offer the basics.

Pizza Bar Toppings Ideas

Pepperoni Pineapple chunks
Red  or Yellow Pepper Slices Ham
Sausage Hamburger
Sliced red onion Jalapenos
Mushrooms slices Onions
Olives Sun-dried Tomatoes
Sliced tomatoes Feta Cheese
Green Peppers Goat Cheese
Spinach Asiago Cheese
Artichokes Garlic Slivers
Anchovies Shredded cheddar

Pizza Ordering Tips

If you want the warmest, freshest possible pizzas, instead of doing pick up yourself, coordinate with your pizza vendor to have the pizza pies delivered right when guests will start eating.   They will deliver the pizzas in insulated bags to ensure they are as warm as possible.  If you really want to pick them up yourself, bring along several thick blankets to keep the pizza temperatures at their highest during the drive.

If you are ordering more than 10 pizzas, you may want to contact your pizza vendor 24 hours in advance to make sure they can prepare everything you need in a timely manner.

Ask about the number of slices per pizza size you are ordering.  Some pizza vendors will slice a large pizza into 8 slices instead of 10.  You can ask them to add an extra two slices per each size to keep the portion size reasonable, especially for large and extra large pizzas.

Which Pizza Size Is The Best Value

Generally speaking, an extra large 18″ pizza gets you the best bang for your buck over other sizes if you use a coupon and ask that it be sliced to 16 slices instead of 14.

Large and extra large pizzas tend to be more economical when you are serving lot of people.  And almost every pizza vendor offers coupons to make the deal even better.

Pizza Size
Pizza Price
Square Inches
Price per sq inch
Sq Inch Per Slice
Price Per Slice
Price Per Slice (sq inches)

Ordering Pizza For Children’s Parties

For children’s parties or when serving pizza as a side item, ask that your medium pizzas be cut to 10 slices instead of 8, or that your large pizzas be cut to 14 slices instead of 12. Children tend to have eyes bigger than their stomachs.  By keeping slices smaller, you will hopefully have less wasted pizza when a child decides they want a second or third slice.

Also keep in mind that although it’s a children’s party, adults will be dropping them off and picking them up. Those same adults might also grab a slice or two, so you may want to get an extra pizza, especially if pick up time is close to a normal lunch or dinner time (when everyone is at their hungriest).

Serving Pizzas

So, you’ve coordinated the delivery of your pizzas so that they are piping hot when guest are ready to eat.  But you don’t have food warming lights to keep the pizzas hot?  Here are a few tips to keep your pizzas warmer longer.

Keeping Pizzas Warm

Make labels or tent cards for each type of pizza.  Pizzas will stay warmer if their boxes aren’t opened too often.  If a box is labeled “Mushrooms”, folks that don’t want mushroom pizza won’t be peeking inside the box.

Stack similar types of pizza.  If your order has (for example) 4 pepperoni pizzas and 4 cheese pizzas, stack the pizza boxes so that only one box of each kind at the top is opened at a time.  This will keep the pizzas warmer because the stacked boxes will help each other retain heat.

Another trick to keeping your pizzas warm without warming lights is to use a heated blanket.  Its large size is perfect for a standard banquet table and it can be hidden from view underneath a tablecloth.

Making Self-Serve Pizza Convenient And Sanitary

Have a pizza slicer and serving tongs on hand.

Sometimes, those pizza slices don’t separate as nicely as they should.  With a pizza slicer on standby, a guest can quickly get their slice out of the box without creating a mess (or stealing cheese off someone else’s slice) and most importantly, without needing to touch the pizza.

Tongs will also make it easier to pick up their slices without needing to touch the rest of the pizza.  You can buy cheap serving tongs at your local dollar store.


This calculator goes on the assumption that pizza is the only food item being served, that the pizzas are standard crust two topping pizza, and that each hungry adult will be eating 3 slices (with adjustments for big and small eaters).

Pizza Size
# of People
# of Pizzas
Big Eaters
Categories: Food, Party Planning