Why Pizza Area Matters More Than Diameter
Most people judge pizza by its diameter, but the amount of pizza you get depends on its area, which grows with the square of the diameter. Doubling the diameter gives you four times as much pizza. This is why “one 18-inch or two 12-inch pizzas?” is such a common question, and why the answer often surprises people. This calculator gives you the exact area of any pizza, its circumference and the area of each slice, and lets you compare two different combinations of pizzas to see which actually gives you more to eat.
How the Pizza Area Calculator Works
- Choose inches or centimeters.
- Enter a pizza’s diameter and, optionally, the number of slices, to see its total area, circumference and area per slice.
- To compare, enter the number of pizzas and diameter for Option A and Option B.
- Press Compare to see the total area of each option and which one gives you more pizza.
- The formulas used are area = π × radius² and circumference = π × diameter.
Example: a 12″ pizza has an area of about 113 in² and a circumference of 37.7″. Cut into 8 slices, each slice is about 14 in².
Pizza Area Calculator FAQs
How do I calculate the area of a pizza?
Divide the diameter by 2 to get the radius, square it, and multiply by π (3.1416). For a 14″ pizza: 7 × 7 × 3.1416 ≈ 154 square inches.
Is one 18-inch pizza bigger than two 12-inch pizzas?
Yes. One 18″ pizza has about 254 in² of area, while two 12″ pizzas have about 226 in² combined. The single 18″ pizza gives you roughly 12% more pizza.
How much bigger is a 16-inch pizza than a 12-inch pizza?
A 16″ pizza has about 201 in² of area compared with 113 in² for a 12″, so it is about 78% bigger even though it is only 4 inches wider.
How big is a 28-inch pizza?
A 28″ pizza has an area of about 616 square inches, more than five times a 12″ pizza. Read more in how big is a 28-inch pizza.
How do I convert pizza size from centimeters to inches?
Divide the diameter in centimeters by 2.54. A 30 cm pizza is about 11.8 inches, very close to a 12″ pizza. The calculator can switch between both units.