Order the right amount of pizza, every time. Tell it how many people and how hungry they are, and it works out how many pizzas to order — plus a size comparison that finds which pizza is the best value per slice of area.
Order
4 🍕
pizzas
Slices needed
30
Slices ordered
32
Leftover
2
Which size is better value?
Compare two pizzas by price per square inch — bigger is usually the better deal.
Pizza A
Value: $0.124 / in²
Pizza B
Value: $0.099 / in²
🏆 Pizza B is the better value — Pizza A costs 24.4% more per square inch.
How to use the pizza calculator
Enter how many people you are feeding, choose how hungry they are, and pick the pizza size. The calculator multiplies people by slices, divides by slices per pizza, and rounds up so nobody goes without — then shows the leftovers. Use the value comparison to decide which size to actually buy.
The pizza maths
pizzas = round up ( people × slices each ÷ slices per pizza )
value = price ÷ area, where area = π × (diameter ÷ 2)²
Because area depends on the square of the diameter, a 16-inch pizza ($20) is far better value than a 12-inch ($14): it has 78% more area for only 43% more money.
Frequently asked questions
A common rule of thumb is three slices per adult and two per child. Multiply the number of people by the slices each, divide by the slices per pizza, and round up. The calculator does this for you and shows how many slices are left over.
It depends on size: a small (about 10 inches) is usually cut into 6 slices, a medium (12 inches) into 8, a large (14 inches) into 10, and an extra-large (16 inches) into 12. You can change the slice count to match your pizzeria.
Almost always — because area grows with the square of the diameter, a 16-inch pizza has more than 2.5 times the area of a 10-inch one, but rarely costs 2.5 times as much. Use the value comparison to check the price per square inch.
For a light meal or when there are sides, two slices per person is plenty. For a main meal or big appetites, plan for three to four. The calculator lets you pick the appetite level.