Pizza Slices Per Person Calculator

How it works

pizza needed = adults × area per adult + children × 55% of that; pizzas = ⌈needed ÷ π(d/2)²⌉; slices = pizzas × slices per pie

The classic rule is three slices of a large per adult, but slices vary wildly with pizza size, so this works in area instead: about 95 square inches per adult for a meal (three 14-inch slices), 60 when pizza is a side and 135 for hungry teenagers. Children eat roughly half. Bigger pizzas are almost always cheaper per square inch — an 18-inch has more than twice the pizza of a 12-inch — so ordering fewer large pies beats many small ones.

Worked example

9 adults and 3 children with normal appetite: 855 + 157 = 1,012 sq in → 7 large 14″ pizzas (56 slices, about 6 spare) at $16 each is $112, or $9.33 a head.

Frequently asked questions