How Many Pizzas Should I Order?

How Many Pizzas Should I Order?

Recently we hosted my son’s 16th birthday party. To make my life easy and serve a bunch of people we decided on ordering pizza.

Once again, we did not order enough pizza pies for the event! I promised that this would be the last time we ran out of pizza or were left with 10 pies too many.

I decided my first quest would be to seek the truth for a baffling question that affects so many people, namely: How many pizzas to buy for a pizza party?

According to national surveys, the average American consumes 27 pounds of pizza a year….serving pizza is always a popular food choice. If you are planning for a party or trying to feed a large group, how many pizzas should you buy for 10, 20, 30 people, or more?

we offer seven distinctive white pizzas

I will show you how to calculate how many pizzas to order so that your guests are satisfied and happy.


This is our official pizza slice calculation!


Number of Guests multiplied by 3 ( avg. slices a person eats) then divide that by 8 (avg slices on a large pizza) = how many pizzas you should order.


Example: 20 guests X 3 slices each = 60 slices of pizza.

Divide 60 slices into 18 and you get 7.5, so you should order 8 pizzas.

Let’s dive into the pizza math:


First, you need to know how many slices your pizza pie will be cut into


Slices can vary between pizzerias and restaurants so it’s always wise to contact the establishment. A general guideline: 6 slices per small (8-10”) pizza, 8 slices per 12 inch pizza (medium), and a large (which can range from 14” to 18”) might have 8, 10, or even 12 slices.


After you’ve called your pizzeria and know how many slices they cut their pies into, then you can get an estimate of how many people they will serve.

  • A small 10” 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” pizza cut into 8 slices and serves 3-5 people
  • A large 16” pizza cut into 8 or 10 slices and serves 5-6 people
  • An 18” pizza is normally cut into 10 or 12 slices and serves 6-7 people


Tip: If your pizzas are the typical 8 slices, that makes each slice one eighth of a pizza. Typically a hungry person can eat 3 slices, so here is a simple equation:


X*⅜  = P 

where X is the number of guests and P is the number you should order


It is important to note that no two pizzas are alike. If you are opting for thin crust pizza, round P up to the nearest pie. For deep-dish, round down. There are other variables in play, like the diameter of the pie and the number of toppings as well as the crowd. Does your crowd contain children, elderly, or those super hungry from sports or other activities? 

Just keep in mind, despite all the philosophical connotations, pizza is supposed to be simple. If I learned anything on my quest it was not to complicate things.