Cake Recipe Scaling Calculator
Scale cake recipes between different pan sizes.
Enter original and new pan dimensions to get the exact ingredient multiplier.
Cake Recipe Scaling adjusts ingredient quantities when you want to use a different pan size than the original recipe calls for. The key is calculating the volume ratio between pans.
The Formula:
Scale Factor = New Pan Volume / Original Pan Volume
Pan Volume Calculations:
For round pans: Volume = π × (diameter/2)² × depth
For square pans: Volume = side² × depth
For rectangular pans: Volume = length × width × depth
Since we are comparing ratios, the units cancel out — you just need the area ratio if both pans have the same depth.
Area Formulas (same depth):
Round pan: Area = π × (d/2)²
Square pan: Area = s²
A 9-inch round pan has an area of about 63.6 square inches. A 9-inch square pan has an area of 81 square inches. So a 9-inch square pan holds about 27% more batter than a 9-inch round pan.
Common Pan Sizes and Areas:
- 6-inch round: 28.3 sq in (182.4 sq cm)
- 8-inch round: 50.3 sq in (324.3 sq cm)
- 9-inch round: 63.6 sq in (410.1 sq cm)
- 10-inch round: 78.5 sq in (506.5 sq cm)
- 12-inch round: 113.1 sq in (729.3 sq cm)
- 8-inch square: 64 sq in (412.9 sq cm)
- 9-inch square: 81 sq in (522.6 sq cm)
- 9×13 rectangular: 117 sq in (754.8 sq cm)
Practical Tips: When scaling up, you may need to reduce the oven temperature by 25°F (about 14°C) and increase bake time, since larger cakes take longer to bake through the center. When scaling down, increase temperature slightly and reduce bake time.
Always fill cake pans only about two-thirds full to allow room for rising. If your scaled recipe produces more batter than the pan can hold, use the extra for cupcakes.
Layer Cakes: For multi-layer cakes, calculate the total volume across all layers. Two 8-inch round layers equal one 8-inch round pan filled twice. If converting from a two-layer 8-inch cake to a single 10-inch layer, calculate the combined volume of both 8-inch layers.
Egg Scaling: Like all baking, eggs are tricky to scale. One large egg weighs about 50 grams (1.75 ounces). If the math calls for a fractional egg, beat the egg and measure by weight.