🎂 Baking
Cake Pan Resizer
Moving a cake to a different pan? Enter the original and new pan dimensions to get the area ratio, volume ratio and recipe multiplier. Press Convert.
About the Cake Pan Resizer
A cake recipe is written for a pan, not for a batter volume. When you change the pan, the batter depth changes unless you scale the recipe. A 9-inch round pan has about 64 square inches of base; an 8-inch square has 64 as well, so those two are close to interchangeable. A 9 × 13 rectangle is 117 square inches — nearly twice the area.
This calculator compares base area and, if you enter depths, volume. Use the volume ratio as the recipe multiplier when you want the same batter depth. If you keep the same batter and change the pan, expect a different depth and a different bake time: shallower cakes bake faster and brown more quickly.
How the calculation works
- Round pan area = π × (diameter ÷ 2)².
- Square pan area = side²; rectangle area = length × width.
- Recipe multiplier = (new area × new depth) ÷ (old area × old depth).
- Linear scale = √(new area ÷ old area).
Reference values
| Pan | Area (sq in) | Compared with 8-inch round |
|---|---|---|
| 6-inch round | 28.3 | 0.56× |
| 8-inch round | 50.3 | 1.00× |
| 9-inch round | 63.6 | 1.27× |
| 8-inch square | 64 | 1.27× |
| 9-inch square | 81 | 1.61× |
| 9 × 13 inch rectangle | 117 | 2.33× |
| 10-inch round | 78.5 | 1.56× |
Worked example: 9-inch round to 9 × 13
A 9-inch round pan has a base area of 63.6 sq in; an 8-inch square is 64 sq in, so those two are almost interchangeable. A 9 × 13 pan is 117 sq in, 1.84× the area of the 9-inch round. For the same batter depth, multiply the recipe by 1.84. If you keep the original batter, the depth falls to 54% and the cake bakes faster.
Match the area first, then adjust the time. A shallower cake browns more quickly, so start checking earlier and reduce the oven temperature slightly if the top sets before the centre. For tall layer cakes, the pan's depth matters as much as its base area.