Cake pan
size converter.
The right recipe, a different pan. Choose round, square or rectangular pans and get an ingredient multiplier for the same batter depth.
Use 126.6% of the original recipe.
63.62 ÷ 50.27 in² = 1.266×
Keep the same batter depth and enough room for rising. This estimates ingredient quantities, not baking time, servings or frosting. Pan material, recipe type and oven behaviour still matter.
How to convert a cake recipe to another pan
Divide the total base area of your new pans by the total base area of the pans in the recipe. Multiply each ingredient quantity by that number. This assumes you want the same depth of batter in each pan.
For example, one 8-inch round pan to one 9-inch round pan gives 9² ÷ 8² = 1.265625. A 200 g ingredient becomes about 253.1 g. Two 8-inch pans to one 8-inch pan gives 0.5: half the original quantity.
For a round pan, area = π × (diameter ÷ 2)². For a square or rectangle, area = width × length. Multiply by the number of pans. Measure the inside at the base and use one unit throughout.
Common cake pan conversions
All examples keep batter depth unchanged. These are mathematical area ratios, not kitchen-tested recipe substitutions.
| Recipe pan | New pan | Multiply by |
|---|---|---|
| 8-inch round | 9-inch round | 1.266 |
| 9-inch round | 8-inch round | 0.790 |
| 8-inch round | 8-inch square | 1.273 |
| 9 × 13-inch rectangle | Two 8-inch rounds | 0.859 |
| Two 8-inch rounds | One 6-inch round | 0.281 |
What this calculator cannot tell you
Changing pan size or material can change how a cake bakes even when you keep the batter depth constant. Follow the original recipe’s doneness cues, check the cake as it bakes and avoid filling the pan too high. Deep, shaped, tube and Bundt pans need a recipe-specific approach.
A very large scale-up is best made as several familiar batches. For fractional eggs, beat the required type of egg and weigh the portion rather than rounding to a whole egg. The multiplier is for the batter: filling and frosting quantities depend on the finished cake’s shape and decoration.
The calculation runs in your browser. Kumora does not send your measurements or ingredient amounts to a server.
Read before you bake
King Arthur Baking explains the area method for alternative pan sizes and why depth and pan material matter. The calculator above uses standard geometry; it does not validate a particular recipe.