Pizza is sold by diameter but eaten by area, and the two do not grow at the same rate. A pizza that is a few inches wider can hold dramatically more food, which is why the biggest size is often the best deal. This calculator compares up to three pizzas by area and price per square inch, and totals your whole order so you can see whether one large beats two mediums.
How to use the pizza size calculator
- Choose inches or centimeters.
- For pizza A and pizza B, enter the diameter, the price and how many you would order.
- Optionally add pizza C to compare a third size or a special deal.
- Optionally enter the width of the plain crust edge to compare the topping-covered area too.
- Read which pizza is the best value per square inch and how your two orders compare in total area and price.
Pizza area and value formulas
Worked example
A pizzeria sells a 14-inch pizza for $16 and an 18-inch pizza for $22:
14-inch: area = π × 7² = 153.9 sq in; $16 ÷ 153.9 = 10.4¢ per sq in
18-inch: area = π × 9² = 254.5 sq in; $22 ÷ 254.5 = 8.6¢ per sq in
The 18-inch pizza has (18 ÷ 14)² = 1.65 times the pizza for 1.38 times the price, so it is about 17% cheaper per bite.
Area of common pizza sizes
| Diameter | Area | Equal to this many 10-inch pizzas |
|---|---|---|
| 8 in | 50 sq in | 0.64 |
| 10 in | 79 sq in | 1.00 |
| 12 in | 113 sq in | 1.44 |
| 14 in | 154 sq in | 1.96 |
| 16 in | 201 sq in | 2.56 |
| 18 in | 254 sq in | 3.24 |
| 20 in | 314 sq in | 4.00 |
Two 12-inch pizzas (226 sq in) hold less than one 18-inch (254 sq in), and a 14-inch is nearly two 10-inch pizzas.
Things the math does not capture
Crust
Every pizza has a rim of plain crust about an inch wide. On a small pizza that rim is a bigger share of the total: on a 10-inch pie, a 1-inch crust leaves only 64% of the area under toppings, versus 79% on an 18-inch. Enter a crust width to see topping area and price per square inch of topping.
Thickness and toppings
Area compares pizzas of the same style. A deep-dish 10-inch can outweigh a thin-crust 14-inch, and specialty pizzas with extra toppings may cost more per square inch for good reason.
Leftovers and variety
Two smaller pizzas let you order two different toppings, and leftovers only count as value if someone eats them. The calculator tells you which is cheapest per bite; the rest is up to your table.
To split the bill afterward, use the split bill calculator. Planning a party? The party food calculator estimates how much food to have. The circle calculator covers any other circle math.
Frequently asked questions
Is one large pizza better than two mediums?
Often, yes. One 18-inch pizza has about 254 square inches, while two 12-inch pizzas have about 226. Unless two mediums cost noticeably less than one large, the large usually gives more pizza per dollar.
How do you calculate the area of a pizza?
Use the circle area formula: π times the radius squared, where the radius is half the diameter. A 14-inch pizza has a radius of 7 inches, so its area is π × 49 ≈ 154 square inches.
Why does a 16-inch pizza have so much more than a 12-inch?
Area grows with the square of the diameter. A 16-inch pizza is 1.33 times as wide as a 12-inch, but (16 ÷ 12)² = 1.78 times the area, so it holds about 78% more pizza.
How many people does a large pizza feed?
A 14- to 16-inch pizza is usually cut into 8 slices and feeds about 3 to 4 adults at 2 to 3 slices each. Hungry teenagers and parties with no other food need more; see the party food calculator for full menus.