Cake Pan Converter
Convert cake recipes between round, square, and rectangular pan sizes using volume equivalents.
Returns the batter multiplier when substituting pan sizes.
Cake pan size conversion allows you to use any pan you own when a recipe calls for a specific size. The key is matching the volume and depth of the original pan, not just the diameter or shape.
Pan Volume Formula:
Round pan volume = π × r² × Depth Square/Rectangular pan volume = Length × Width × Depth
Standard pan volumes (2-inch deep):
| Pan Size | Volume |
|---|---|
| 8-inch round | 25 cu in |
| 9-inch round | 32 cu in |
| 9×13 rectangular | 117 cu in |
| 8×8 square | 64 cu in |
| 9×9 square | 81 cu in |
| 10-inch bundt | 80 cu in |
| 9×5 loaf | 68 cu in |
Scaling batter between pans:
Scale Factor = New Pan Volume / Original Pan Volume Multiply all ingredient quantities by the scale factor.
Worked example: Recipe calls for a 9-inch round pan (32 cu in). You have an 8-inch round pan (25 cu in). Scale factor = 25 / 32 = 0.78 (use 78% of each ingredient) Or: Use two 8-inch pans and bake as a two-layer cake.
Baking time adjustment:
- Shallower batter (wider pan): reduce time by 10–15%, check earlier
- Deeper batter (narrower pan): increase time by 15–25%, use toothpick test
- Rule of thumb: Every 25% change in batter depth changes bake time by about 10%
Practical substitutions that work without scaling:
- Two 8-inch rounds ≈ one 9×13 (same volume, use both layers)
- One 9-inch round ≈ one 8×8 square (similar depth and volume)
- One 9×5 loaf ≈ one 8-inch round
Always grease and flour pans properly regardless of size — sticking is more likely with odd-shaped pans.