Pizza calculator
How many pizzas do you need? Tell us who’s coming and how hungry they are. We’ll do the pizza math.
plus 0 small pizzas, gluten-free
72 slices for 20 grown-ups. That’s about 3 each, plus 12 spare for whoever said “I’m not that hungry.”
Suggested delivery tip (15%, at least $5):
Feeding the whole office?
Past 20 people, compare catering on cost per head before you order a tower of pizza boxes. Someone else brings the plates.
How the pizza calculator works
Every answer starts with slices, not pizzas. Each grown-up gets 3 slices (2 if they’re nibblers, 4 if they’re starving) and each kid gets 2. If you’re also serving wings, salad or other food, we count 75% of that. Then we add 10% so the last person in line still gets a slice, and divide by the slices in the size you’re ordering: 6 in a small, 8 in a medium, 8 in a large and 12 in an extra-large. Anything with a fraction rounds up, because nobody sells a quarter of a pizza.
Not sure how big a large is where you’re ordering? Our guide to how many slices are in a large pizza compares the sizes.
Why 9 pizzas for 20 people, not 8?
Twenty grown-ups at 3 slices each need 60 slices, and 8 large pizzas hold 64. That’s 4 spare, gone once 4 people go back for a fourth slice. Our 10% cushion takes the count to 9, which is the answer on our how many pizzas for 20 people page too. If you’d rather cut it close, pick Nibblers or turn on “Also serving other food.”
Ordering an office lunch
Switch to Office lunch and the calculator adds what a team order needs: how many vegetarians and gluten-free eaters you have, what a pizza costs you, and an optional budget per person. It shows the order total and the cost per person, so you can check a team lunch against the budget before you call it in. Feeding 20 or more? Our office catering guide covers when catering beats pizza boxes.
Share the order
Every change updates the web address, so you can copy the link and send the exact order to whoever’s picking it up.