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Pizza Calculator

Work out how many pizzas to order so nobody goes hungry and you are not eating leftovers for a week. Enter the number of adults and children, how many slices each will eat and how many slices your pizzas are cut into; add a price to see the total cost.

Quick examples

2 for light eaters or with lots of sides, 4 for a hungry crowd.

$
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Pizzas to order3
Slices needed
24
Slices left over
0
Total cost
$45.00

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      Formula

      Slices needed = adults × slices per adult + children × slices per child
      Pizzas to order = slices needed ÷ slices per pizza, rounded up
      Slices left over = pizzas × slices per pizza − slices needed

      How to use it

      1. Enter the number of adults and children.
      2. Adjust slices per person for how hungry the group is.
      3. Choose how many slices each pizza has.
      4. Add the price per pizza to see the total.

      Worked examples

      Eight adults eating three slices each, with 8-slice pizzas at $15

      Slices needed
      24
      Pizzas to order
      3
      Slices left over
      0
      Total cost
      $45.00

      Ten adults and six children with 8-slice pizzas at $14

      Slices needed
      42
      Pizzas to order
      6
      Slices left over
      6
      Total cost
      $84.00

      The 3/8 rule

      The standard shortcut is three slices per adult from an 8-slice pizza: multiply the number of guests by 3, divide by 8 and round up. Eight people need 3 pizzas, 20 people need 8, and 30 people need 12.

      Plan on two slices for children and light eaters, or when there are plenty of sides, salad and dessert. Plan on four for teenagers, sports teams and parties where pizza is the only food.

      Sizes and slices

      Chains vary, but typical cuts are: small (10 inch) 6 slices, medium (12 inch) 8 slices, large (14 inch) 8 slices and extra large (16–18 inch) 10 to 12 slices. Slices from a bigger pizza are bigger too, so count on fewer per person.

      Bigger pizzas are usually better value. A 16-inch pizza has about 201 square inches of pizza against 113 for a 12-inch — 78% more food, typically for far less than 78% more money.

      Questions people ask

      How many pizzas do I need for 10 people?

      Four 8-slice pizzas. Ten people at three slices each is 30 slices; 30 ÷ 8 = 3.75, rounded up to 4.

      How many pizzas do I need for 20 people?

      Eight 8-slice pizzas (60 slices ÷ 8 = 7.5, rounded up).

      How many slices are in a large pizza?

      Usually 8, sometimes 10. A medium is normally 8 smaller slices and a small is 6.

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