Scale cake batter between round pan sizes by comparing their surface area.
Usage Tip
For square pans, use side length squared instead of the circle area formula.
Popular pan conversions
How cake pan conversion works
Batter fills a pan by area, not by width, so scale the recipe by the ratio of the two pan areas. A round pan area is π × radius²; a square or rectangular pan is length × width. Divide the new pan area by the old one to get the multiplier.
Common pan sizes by area
| Pan | Area (sq in) |
|---|---|
| 6" round | 28 |
| 8" round | 50 |
| 9" round | 64 |
| 10" round | 79 |
| 8×8 square | 64 |
| 9×9 square | 81 |
| 9×13 rectangle | 117 |
| 8.5×4.5 loaf | 38 |
Common pan swaps
| From | To | Multiply batter by |
|---|---|---|
| 8" round | 9" round | × 1.26 |
| 9" round | 8" round | × 0.79 |
| 8" round | 10" round | × 1.56 |
| 9" round | 9×13 | × 1.84 |
| 8×8 square | 9×13 | × 1.83 |
| 9×13 | 9" round | × 0.54 |
Useful to know: a 9-inch round pan and an 8×8 square hold almost the same amount, so you can usually swap them with no change.
Common pan questions
Can I use a 9-inch pan instead of an 8-inch?
Yes. A 9-inch round holds about 26% more than an 8-inch, so the cake will be thinner and bake a little faster – or scale the batter up by 1.26 to keep the same height.
How do I swap an 8×8 for a 9×13?
A 9×13 holds about 1.83 times an 8×8, so nearly double the recipe to fill it to the same depth.
Can I bake a round recipe in a square pan?
Yes, just match the areas. A 9-inch round (64 sq in) is almost identical to an 8×8 square, so no change is needed.