How Many Pizzas Should You Order To Feed 20 People?

The task of ordering pizza for a group also comes with good news and with bad news. The good news: Everybody gets pizza! The bad news: Somebody has to figure out how many pizzas to acquire.

Now, this undertaking is further complicated by the vast and varied types of pizza in existence. The amount of Detroit-style pizza required to adequately satisfy 20 people will be different than the amount of Chicago's deep dish, or even its lesser-known tavern-style. For the most achievable possibility of success, consider the most common kind of pizza: The round pie of an average crust thickness, cut into triangles. It's the image that typically appears when a person hears the word "pizza," the Central Casting example of the form.

If money is no object, and leftovers can be appropriately dispatched to reduce food waste, then you can make a liberal guesstimate. But in everyday instances where neither scenario is the case, you need a real calculation. And the conventional pizza equation recommended by big chains and smaller operators lands on eight pizzas for 20 people.

Regional differences and shop-to-shop quirks aside, the typical large pizza is 14 inches in diameter, divided into eight slices. While there's no accounting for appetite size, the common formula, called the ⅜ rule, allows for an average of three pieces of pizza per guest. That means, of course, that eight pizzas divided into eight slices each comes out to 64 slices total, which is just over the minimum amount required to suitably accommodate 20 people. The math works whether you're ordering from one of America's most popular pizza chains or the corner spot.

As a host — or the person made responsible for ordering the pizzas — you'll also want to create the appearance that there's always more. The last thing you want is for your guests to think anything is in short supply. And the worst possible outcome of ordering eight pies for your group of 20 is that you're left with a manageable amount of "extra pizza" — a phrase that some say doesn't even exist.