Pizza Size Calculator: Which Is the Better Deal?
Which pizza order gives you more pizza for your money, one large or two smaller.
Good to know. One 18-inch pizza has more pizza than two 12-inch ones. Area grows with the square of the size.
How it works
In plain words
A pizza’s area is π times the radius squared, so doubling the diameter gives four times the pizza. Multiply by the number of pizzas, divide by the price, and compare.
The formula
area = number × π × (diameter ÷ 2)² value = area ÷ price
Worked example
One 16-inch pizza for 18 is 201 square inches; two 12-inch pizzas for 24 are 226. Order B is 12.5% more pizza, but order A gives more pizza for the money, by 18.5%.
Sources
No outside data or rates: this is plain arithmetic.
4 automated tests check its answers on every change.
About this calculator
Pizza sizes are quoted by diameter, but what you eat is area, and area grows with the square of the diameter. A 16-inch pizza isn’t a third bigger than a 12-inch one; it has about 78% more pizza.
That is why one large pizza so often beats two smaller ones. One 18-inch pizza (about 254 square inches) has more pizza than two 12-inch pizzas (about 226), and usually costs less. Menus rarely price sizes in proportion to their area, so the largest size tends to be the best value.
This calculator compares two orders: the number of pizzas, their diameter and the total price for each. It tells you which gives more pizza in total and which gives more pizza for the money, which is not always the same order.
Crust counts as pizza here. If you don’t eat the crust, the larger pizza wins by even more, since a bigger share of a small pizza is crust. To split the bill afterwards, use the split the bill calculator; to scale a homemade dough recipe up or down, the recipe scaler.
Questions people ask
Is one large pizza better than two medium ones?
Often, yes. One 18-inch pizza has more area than two 12-inch ones; check the prices here to see which is better value.
How much bigger is a 16-inch pizza than a 12-inch one?
About 78% more pizza: 201 square inches against 113.
How do I work out the area of a pizza?
π × radius². For a 30 cm pizza, the radius is 15 cm, so 3.14 × 225 ≈ 707 cm².