Why size matters more than you think
People tend to compare pizza sizes by diameter, but you eat the area. Doubling the diameter quadruples the pizza. Moving from a 10-inch to a 14-inch pizza adds only four inches to the width but nearly doubles the area, from 79 to 154 square inches.
That is why restaurants can charge a little more for a large and still make it the better deal for you. This calculator turns the menu prices into one number that is easy to compare: what you pay per unit of pizza.
A worked example
Suppose a 12-inch pizza costs 14 and a 16-inch costs 20. The areas are 113.1 and 201.1 square inches. The small one costs 12.4 per 100 square inches and the large one costs 9.9 per 100. The large pizza gives 78% more pizza for 43% more money, which makes it about 20% cheaper per square inch.
Tips for comparing pizza deals
Check the actual diameter, because one chain’s medium may be another’s large. If there is a deal such as two for one, add up the areas and divide the total price by them to get the price per square inch, then compare that with the other pizza’s figure.
Remember that a bigger pizza is only a better deal if you will eat it. Leftovers keep well, and cold pizza is a reasonable breakfast, but food you will not eat is never good value.
Questions people ask
Is a bigger pizza really better value?
Usually, yes. The amount of pizza depends on the area, which grows with the square of the diameter. A 16-inch pizza has 78% more pizza than a 12-inch one, even though it is only a third wider. Unless the large one is priced very steeply, it is the better deal.
How is the area of a pizza calculated?
Area = π × (diameter ÷ 2)². A 12-inch pizza has a radius of 6 inches, so its area is 3.1416 × 36 = 113.1 square inches. We then divide the price by the area to get the cost for each square inch, and show it per 100 for readability.
Are two small pizzas better than one large one?
Add up the areas. Two 10-inch pizzas total 157 square inches, slightly more than one 14-inch pizza at 154. So if two 10-inch pizzas cost less than a 14-inch, they are the better deal. To check a combination in the calculator, divide the total price by the total area and compare it with the other pizza’s price per square inch.
Should I measure the pizza or the box?
Measure or check the pizza itself. Pizza sizes are quoted as the diameter of the pizza, and a box is usually a bit larger. Some chains use sizes such as “large” loosely, so check the listed inches or centimetres on the menu.
Does the calculator count toppings and crust?
No. It compares area only, so a thick-crust pizza or one with more toppings may not be directly comparable. If two pizzas are very close in value, pick the one you would enjoy more.