Parties & Family calculator
Plan whole pizzas from guest portions and actual pizza diameter, with leftovers and ordering cost.
8 adults eating 3 slices and 4 children eating 2 need 32 slices, or 35.2 with a 10% allowance. At 8 slices per pizza that is 5 pizzas (40 slices), costing 60 at 12 each.
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Enter portions for the pizza size you are ordering; slicing one pizza more finely does not create more food.
Scale a known slice plan by pizza area when crust thickness and toppings are comparable.
8 adults eating 3 slices and 4 children eating 2 need 32 slices, or 35.2 with a 10% allowance. At 8 slices per pizza that is 5 pizzas (40 slices), costing 60 at 12 each.
| Input | Value |
|---|---|
| Adults | 8 |
| Children | 4 |
| Slices per adult | 3 |
| Slices per child | 2 |
| Slices per pizza | 8 |
| Extra allowance | 10 % |
| Price per pizza | 12 |
| Result | Value |
|---|---|
| Portions including allowance | 35.2 reference slices |
| Pizzas to order | 5 |
| Equivalent slices left over | 4.8 reference slices |
| Order cost | 60 |
It first estimates the required slices, then divides by slices per pizza and rounds up. A requirement of 35.2 slices at eight slices per pizza means five pizzas. The appetite rates are editable assumptions; starters, other food and actual pizza sizes can change the plan.
Area changes with the square of the diameter. A 35 cm pizza has about 1.361 times the area of a 30 cm pizza, assuming similar shapes. Thickness and topping density are not captured by that area comparison, so it is a portion-planning aid rather than an exact equivalence.
Adjust the stated slices-per-person assumptions to reflect the rest of your menu before calculating the number of pizzas. Keep adults, children and the reserve visible so that you can explain the result. The estimate depends on those inputs and actual slices per pizza; it does not guarantee each guest's appetite.
Calculation/content reviewed 4 October 2026. Source: Babushka Market’s displayed formulas, units and labelled editable assumptions. How the estimates work
