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Pizza calculator (how many to order)

Find out how many pizzas to order for your group, from headcount, appetite and slices per pizza. Example: 10 adults with a normal appetite ≈ 4 large pizzas.

Pizzas to order
4
Slices needed30
Leftover slices2

Slice-based estimate. Drinks, starters and dessert reduce pizza intake; a variety of flavors tends to increase it.

Interactive lesson: The large pizza always wins From medium to large you don't get 33% more — you get 78%. Find out why area grows with the square.

How the calculation works

We multiply people by the slices each eats and divide by the slices in a pizza, rounding up: pizzas = ceil(people × slices per person ÷ slices per pizza). A practical average is 3 slices per person.

Examples

  • 10 people × 3 slices ÷ 8 per pizza = 3.75 → 4 pizzas.
  • A hungry group (4 slices/person): always round up.

Frequently asked questions

How many slices in a pizza?

A large pizza usually has 8 slices; family size, 10 to 12. Adjust the field to your pizzeria.

How many slices does a person eat?

About 3, but it varies: kids and those having starters eat less; hungry adults, more.

Do different flavors change the count?

Not the total, but half-and-half lets you offer more variety without ordering more.

Do two medium pizzas beat one large?

Not always — compare by area. A 30 cm pizza has 707 cm² and a 40 cm one 1,257 cm², 78% more.

How many pizzas for 20 people?

With a normal appetite (3 slices each) and large 8-slice pizzas, 8 pizzas. Adjust down for children and up for teenagers.

How do I know which size is the better deal?

Divide price by area, not diameter. Area is π × (diameter ÷ 2)². Price per square centimetre usually favours the larger pizza.

How many flavours should I order?

About one flavour per 4–5 people, always including a simple option. Half-and-half pizzas cover two tastes each.

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Updated on June 30, 2026 · by Rafael Rossi · Methodology & sources