Baking Pan Size Converter
Use this pan size converter to swap a round, square or rectangular baking pan for another size and see exactly how much to multiply your recipe by.
Compare two baking pans
Measure the inside of the pan across the top edge. The result assumes straight sides and the same batter depth in both pans. For loaf, fluted or sloping pans, compare how much water each holds instead.
How the pan size converter works
When you bake the same batter to the same depth, the amount you need depends on the area of the bottom of the pan. The pan size converter works out both areas and divides one by the other to give a single multiplier for the whole recipe:
round pan area = π × (diameter ÷ 2)²
square pan area = side × side and rectangular pan area = length × width
multiply the recipe by = area of your pan ÷ area of the recipe’s pan
Because both areas use the same unit, the multiplier is the same whether you measure in inches or centimetres. The converter also shows which round and square pans have the same area as the recipe’s pan, which is useful when you can choose between pans you already own.
Worked example: 9-inch round to 9 × 13
A 9-inch round pan has an area of π × 4.5² = 63.6 sq in. A 9 × 13 inch pan has 9 × 13 = 117 sq in. Dividing 117 by 63.6 gives 1.84, so the recipe needs about 1.84 times every ingredient, which is 84% more batter. In practice, many bakers would make 1¾ or 2 times the recipe and adjust how full the pan is.
Common baking pan areas
| Pan | Area | Pan | Area |
|---|---|---|---|
| 8-inch round | 50.3 sq in | 20 cm round | 314.2 cm² |
| 9-inch round | 63.6 sq in | 22 cm round | 380.1 cm² |
| 10-inch round | 78.5 sq in | 24 cm round | 452.4 cm² |
| 8-inch square | 64 sq in | 20 cm square | 400 cm² |
| 9-inch square | 81 sq in | 23 cm square | 529 cm² |
| 9 × 13 inch | 117 sq in | 30 × 20 cm | 600 cm² |
Two pans with similar areas can share a recipe without scaling. A 9-inch round and an 8-inch square, for example, are within 1 sq in of each other.
Does baking time change with pan size?
Yes, but not by a formula. When you scale the batter to the new area, its depth stays about the same, so the baking time is usually close to the original. If you do not scale, the batter is deeper in a smaller pan and needs longer, and thinner in a larger pan and bakes faster. Keep the oven temperature from the recipe, start checking a little early, and judge doneness with a skewer, a gentle press or the test the recipe gives.
How do I measure a baking pan?
Measure across the inside of the pan at the top edge, not the outside or the base. Many pans have sloped sides and rounded corners, so their real base is slightly smaller than the top measurement suggests; for everyday baking the difference is small. For deep, fluted or loaf pans, compare their volume instead: fill each with water and measure how much it holds.
Scaling the recipe after converting
Once you have the multiplier, apply it to every ingredient. In the recipe scaler, enter 1 as the servings the recipe makes and the multiplier as the servings you need, then paste the ingredients. Eggs rarely divide neatly: beat them together and weigh or measure the part you need. If the recipe uses cups, our kitchen unit converter helps you switch between cup and spoon measures. For more ideas to bake, browse our recipes.
With the right multiplier from the pan size converter, the batter fills the new pan to the depth the recipe was written for.
Frequently Asked Questions
Divide the area of your pan by the area of the pan in the recipe, then multiply every ingredient by the result. A 9 × 13 inch pan (117 sq in) holds about 1.84 times as much batter as a 9-inch round (63.6 sq in) at the same depth, so a recipe for the round pan needs to be multiplied by about 1.84.
Yes, they are close. Two 9-inch rounds have about 127 sq in of base, and a 9 × 13 pan has 117 sq in, so the same batter will sit roughly 9% deeper in the rectangle. Keep the temperature the same and expect it to need a little longer; test for doneness rather than relying on the clock.
An 8-inch round pan has an area of about 50.3 sq in, the same as a square pan of about 7.1 inches. A 7-inch square is the nearest common size; an 8-inch square has about 27% more area, so the batter would be thinner.
Usually not. Keep the temperature from the recipe and adjust the time instead: thinner layers of batter bake faster and deeper ones take longer. Start checking early, and use a skewer or the recipe’s doneness test.
Springform pans are round, so enter their diameter. Loaf and Bundt pans are deep or shaped, so their base area does not tell you how much they hold. To compare those, fill each pan with water, measure the volumes and divide one by the other.