Pizza Party Calculator
Hosting a party and not sure how much pizza you’ll need? Try our Pizza Calculator — it quickly estimates the right amount based on your guest count, appetite level, and pizza size.
The Pizza Formula
To estimate how many pizzas you need, use this formula:
p = 3a / s
Where:
p= Number of pizzasa= Number of adults or guestss= Number of slices per pizza
We assume each person eats about 3 slices on average. You can change this in the calculator based on hunger level (2, 3, or 4 slices per person).
How Many Pizzas Should You Order?
Here’s a quick breakdown of how many pizzas you’ll need based on average hunger:
| Number of People | Light Hunger (2 slices/person) | Medium Hunger (3 slices/person) | Heavy Hunger (4 slices/person) |
|---|---|---|---|
| 5 | 2 pizzas | 2 pizzas | 3 pizzas |
| 10 | 3 pizzas | 4 pizzas | 5 pizzas |
| 15 | 4 pizzas | 6 pizzas | 8 pizzas |
| 20 | 5 pizzas | 8 pizzas | 10 pizzas |
| 30 | 8 pizzas | 11 pizzas | 15 pizzas |
Tip: Always round up. It’s better to have extra pizza than not enough.
How Many Slices Are in a Pizza?
How many slices you get from a pizza varies depending on its size and the way it’s sliced. Here’s a quick guide:
| Pizza Size (inches) | Typical Slices |
|---|---|
| 8″ (Personal) | 4 slices |
| 10″ (Small) | 6 slices |
| 12″ (Medium) | 8 slices |
| 14″ (Large) | 8–10 slices |
| 16″ (Extra Large) | 10–12 slices |
| 18″ (Party Size) | 12–14 slices |
When using the calculator, make sure to enter how many slices your chosen pizza size typically has.
Slice to Pizza Size Ratio
Larger pizzas give you more slices and better value. For example:
- Two 12″ pizzas (8 slices each) = 16 slices
- One 16″ pizza (12 slices) is almost the same but often costs less
That’s why it’s helpful to consider pizza size and slicing when ordering for a group.
Pro Tips When Ordering Pizza for a Group
- Know your crowd: Kids eat fewer slices than adults. Teenagers or sports teams eat more.
- Choose mixed toppings: Go for half cheese, half pepperoni, or veggie/meat combos to satisfy everyone.
- Account for sides: If you’re serving sides (wings, salad, etc.), you can order fewer pizzas.
- Always round up: Leftovers are better than running out.
Try the Pizza Calculator
Instead of guessing, use our Pizza Calculator above. Just enter how many people you’re serving, choose their hunger level, and select the pizza size. The tool gives you instant pizza order suggestions — and you can easily share the results with friends or your event organizer.