# Pizza Party Calculator – How Many Pizzas to Order

URL: https://speedycalculator.com/calculators/food/pizza-party/
Last updated: 2026-10-30

> The pizza party calculator works out how many pizzas to order for a party – by the number of adults and children, their appetite and the pizza size – plus the total cost, cost per person and calories per person.

## Inputs

- Adults
- Children
- Appetite
- Pizza size
- Pizza type
- Price per pizza

## Results

- Slices per pizza
- Slices needed
- Pizzas to order
- Leftover slices
- Total cost
- Cost per person
- Calories per adult (approx.)

## Formula

```
Slices needed = adults × slices per adult + children × 2
Pizzas = ⌈slices ÷ slices per pizza⌉
Calories per slice ≈ calories per in² × pizza area ÷ slices
```

## Explanation

Plan about 3 slices of a large pizza per adult (2 for light eaters, 4 for big appetites and teenagers) and 2 for children. Order a mix of plain cheese, pepperoni and a vegetarian option, and remember leftovers are rarely a problem.

### How to use the Pizza Party Calculator – How Many Pizzas to Order

- **Adults**
- **Children**
- **Appetite**
- **Pizza size**
- **Pizza type**
- **Price per pizza**

Results update as you type, and every field accepts the units shown in its menu.

### How it works

Enter the number of adults and children, their appetite, the pizza size and type, and the price per pizza.

### Tips

- Order by area, not by diameter: a 16" pizza has almost twice the area of a 12" one.
- Plan about 3 slices per adult for a meal, more for big appetites and teenagers.
- For homemade pizza, cold-ferment the dough for 24–72 hours for better flavour.
- Preheat the oven and the stone or steel for at least 45 minutes.

### Common mistakes to avoid

- Comparing prices per pizza instead of per square inch.
- Forgetting that a thick crust eats into the topping area of a small pizza.
- Over-topping homemade pizza, which leaves the middle soggy.

### Inputs explained

FieldWhat to enterAdultsA numberChildrenA numberAppetiteChoose one: Light – 2 slices each, Average – 3 slices each, Hungry – 4 slices each, Teen athletes – 5 slices eachPizza sizeChoose one: Small (10 in / 25 cm), Medium (12 in / 30 cm), Large (14 in / 36 cm), Extra large (16 in / 40 cm) …Pizza typeChoose one: Cheese, Veggie, Pepperoni, Meat lovers / bacon and cheese …Price per pizzaAmount in your currency

### What each result means

- **Slices needed** = [Adults]×[Appetite] + [Children]×2
- **Pizzas to order** = ceil([Slices needed]÷[Slices per pizza])
- **Leftover slices** = [Pizzas to order]×[Slices per pizza] - [Slices needed]
- **Total cost** = [Pizzas to order]×[Price per pizza]
- **Cost per person** = [Total cost]÷([Adults] + [Children])

### Example values

How the main result changes when **Adults** changes and everything else stays at the example values above:

AdultsPizzas to order537.5410412.55156207

## Worked example

Inputs — Adults: 10; Children: 4; Appetite: Average – 3 slices each; Pizza size: Large (14 in / 36 cm); Pizza type: Cheese; Price per pizza: $16.

Results — Slices per pizza = 10; Slices needed = 38; **Pizzas to order = 4**; Leftover slices = 2; Total cost = $64.00; Cost per person = $4.57; Calories per adult (approx.) = 647 kcal.

## FAQ

**How many pizzas for 20 people?**
About 6–8 large pizzas (10 slices each) at 3 slices per adult.

**How many slices are in a large pizza?**
Usually 8–10 for a 14 in pizza.

**How many pizzas do kids eat?**
About 2 slices of a large pizza per child.