How the baking pan converter works
A recipe is written for a certain pan. Pour the same batter into a bigger pan and the layer gets thinner; pour it into a smaller one and the layer gets thicker. To get the same result in another pan, you want the same depth of batter. Batter depth stays the same when the amount of batter grows or shrinks by exactly as much as the bottom area of the pan. That is why this converter compares pan areas: the factor is the area of the new pan divided by the area of the recipe pan, and every ingredient gets multiplied by it.
A cake, a pan of brownies, a sheet of focaccia or a loaf of banana bread all follow the same idea, so you can use the converter for any recipe that bakes in a pan with straight or slightly sloped sides. The size of a round pan is its diameter, the distance straight across the middle. Measure the inside of the pan, from inner edge to inner edge, because that is the space the batter fills.
Example: a recipe for an 8 inch round pan, baked in a 9 inch round pan. The 8 inch pan has π × 4² = 50.3 square inches, the 9 inch pan π × 4.5² = 63.6 square inches. 63.6 ÷ 50.3 = 1.27, so you multiply every ingredient by about 1 1/4. One inch more across means about 27% more batter.
Why one inch matters so much
The area of a round pan grows with the square of its diameter. Double the diameter and the area, and with it the batter, grows four times. That is why a 12 inch round needs four times the batter of a 6 inch round, and why a 10 inch round needs more than 1.5 times the batter of an 8 inch round (78.5 against 50.3 square inches). In centimeters the same rule holds: a 26 cm springform has about 531 cm², a 20 cm one about 314 cm², so a recipe for the 26 cm pan scales to about 0.59, a little under 5/8, for the 20 cm pan.
Round, square and rectangle pans
Pans of different shapes can hold the same amount of batter. A round pan has π ÷ 4, about 79%, of the area of a square pan of the same width. So a 9 inch round pan (63.6 square inches) and an 8 inch square pan (64 square inches) are almost the same, and you can swap one for the other without changing the recipe. A recipe for two 9 inch round layers, about 127 square inches together, fits a 13 x 9 inch rectangular pan with 117 square inches, a little deeper. For a rectangle, it does not matter whether you enter 13 x 9 or 9 x 13: the area is the same.
Pans with sloped sides are a bit wider at the top than at the bottom. Measure them across the top inside edge and treat the factor as a close estimate. For a pan of an unusual shape, choose Area and enter its area if you know it.
When to include the depth
Scaling by area keeps the batter as deep as the recipe intended. If your new pan is much deeper or shallower and you want to fill it to the same share of its height, choose Area and depth. The factor then compares the pan volumes: area times depth. A 9 inch round that is 3 inches deep gets 1.5 times the batter of the same pan that is 2 inches deep.
What the converter does not change
The converter scales amounts. It does not change the baking time or the oven temperature, and we have not found an official or reliable published rule for doing that by pan size. A different batter depth can change the time. Keep the temperature from the recipe, start checking a good while before the stated time and bake until the doneness test in your recipe is met.
A few things need judgment when you scale. Eggs rarely come out whole: beat an egg and measure out the share you need. Kitchen fractions get easier with the cooking measurement converter, which turns 1 7/8 cups into cups and spoons, and cups to grams helps if you would rather weigh. To scale a recipe by servings instead of by pan, use the recipe scaler.
Baking pan sizes and their areas
Inside measurements and areas of pan sizes, in square inches and square centimeters. Divide the area of the pan you have by the area of the pan in your recipe to get the factor.
| Pan | Square inches | cm² |
|---|---|---|
| 6 in round | 28.3 | 182.4 |
| 8 in round | 50.3 | 324.3 |
| 9 in round | 63.6 | 410.4 |
| 10 in round | 78.5 | 506.7 |
| 12 in round | 113.1 | 729.7 |
| 8 x 8 in square | 64 | 412.9 |
| 9 x 9 in square | 81 | 522.6 |
| 8.5 x 4.5 in loaf | 38.3 | 246.8 |
| 9 x 5 in loaf | 45 | 290.3 |
| 11 x 7 in rectangle | 77 | 496.8 |
| 13 x 9 in rectangle | 117 | 754.8 |
| 15 x 10 in rectangle | 150 | 967.7 |
| 18 x 13 in rectangle | 234 | 1,509.7 |
| 18 cm round | 39.4 | 254.5 |
| 20 cm round | 48.7 | 314.2 |
| 22 cm round | 58.9 | 380.1 |
| 24 cm round | 70.1 | 452.4 |
| 26 cm round | 82.3 | 530.9 |
| 28 cm round | 95.4 | 615.8 |
| 20 x 20 cm square | 62 | 400 |
| 24 x 24 cm square | 89.3 | 576 |
| 25 x 11 cm loaf | 42.6 | 275 |
| 30 x 11 cm loaf | 51.2 | 330 |
| 30 x 20 cm rectangle | 93 | 600 |
| 34 x 24 cm rectangle | 126.5 | 816 |
| 40 x 30 cm rectangle | 186 | 1,200 |
How to use the baking pan converter
- 1Choose inches or centimeters, then the shape and size of the pan in your recipe.
- 2Enter the shape and size of the pan you want to use, or tap a size in the comparison table.
- 3Multiply every ingredient by the factor, or paste the ingredient list to have it scaled for you, then bake until the recipe's doneness test is met.
Frequently asked questions
How do I convert a recipe from a 9 inch round pan to a 9 x 13 pan?
A 9 inch round pan has about 63.6 square inches, a 13 x 9 inch pan 117 square inches. 117 ÷ 63.6 is about 1.84, so multiply every ingredient by about 1 7/8 to get the same batter depth. Two 9 inch rounds together have about 127 square inches, so a recipe for a two layer 9 inch cake fills a 9 x 13 pan a little deeper than its rounds.
Can I use an 8 inch square pan instead of a 9 inch round?
Yes, by area they are almost the same: 64 square inches for the 8 inch square and about 63.6 for the 9 inch round. The calculator gives a factor of 1.01, so the recipe stays as it is.
How do I convert a round cake pan to a square pan?
Choose Round for the recipe pan and enter its diameter, then choose Square for the new pan and enter its side. The calculator divides the square area (side × side) by the round area (π × radius²) and gives the factor. A round pan has about 79% of the area of a square pan with the same width.
Does the baking time change with a different pan?
It can, because the batter is spread differently. The calculator keeps the batter depth the same when you scale by area, but it does not predict a new baking time, and we know of no reliable published rule that does. Keep the oven temperature from the recipe, start checking before the stated time and bake until the doneness test in your recipe is met.
What if the new pan is deeper than the old one?
Choose Area and depth and enter both depths. The factor then compares volumes, so the batter fills the new pan to the same share of its height. With Area alone, the factor keeps the batter just as deep as in the old pan.
How do I scale a recipe down for a smaller pan?
Halving the diameter of a round pan quarters its area. A 6 inch round has about 28.3 square inches and an 8 inch round about 50.3, so the 6 inch pan needs about 56% of the 8 inch recipe, a little more than half. Enter both pans and use the factor shown. For eggs, beat a whole egg and measure out the share you need, or paste the ingredient list into the box below the result.