FlourScaleHow pan conversion works
When you move a recipe into a different pan, what matters is the area of the pan's base. If the new pan has the same area, the batter will be the same depth and the recipe can be used as written, with a similar baking time. If the new pan is larger, you need more batter to reach the same depth; if it is smaller, you need less. The scaling factor is simply the new area divided by the original area.
- Round pan area = π × (diameter ÷ 2)²
- Square pan area = side × side
- Rectangular pan area = length × width
Multiply every ingredient in the recipe by the factor. The calculator links straight to our recipe scaler with the factor filled in, so you can paste the ingredient list and get the new quantities in seconds.
Common pan areas
| Pan | Area (sq in) |
|---|---|
| 6-inch round | 28.3 |
| 8-inch round | 50.3 |
| 9-inch round | 63.6 |
| 10-inch round | 78.5 |
| 8 × 8 inch square | 64 |
| 9 × 9 inch square | 81 |
| 11 × 7 inch | 77 |
| 13 × 9 inch | 117 |
| Half sheet, 18 × 13 inch | 234 |
Two useful takeaways: a 9-inch round and an 8-inch square are almost identical, and a 9 × 13 pan holds a little less than two 9-inch rounds (117 vs 127 sq in). A recipe for two 9-inch layers will fill a 9 × 13 slightly deeper than the layers were.
Worked example
You have a recipe for an 8-inch round cake but want to bake it in a 10-inch round.
- 8-inch area = 3.1416 × 4² = 50.3 sq in
- 10-inch area = 3.1416 × 5² = 78.5 sq in
- Factor = 78.5 ÷ 50.3 = 1.56
Multiply each ingredient by about 1.56 — 200 g of flour becomes about 312 g. Three eggs become 4.7, so use 4 large eggs plus a little extra beaten egg, or see our egg size calculator.
Practical tips
- Pan depth matters too. This converter assumes both pans have similar sides (around 2 inches). Never fill a cake pan more than about two-thirds full.
- Adjust the bake time. A pan with the same area bakes in about the same time; use our baking time calculator when the depth changes.
- Measure inside edges. Pans are often labelled by their top dimensions, which can be larger than the base.
- Dark vs light pans. Dark or glass pans brown faster; many bakers lower the oven by 25°F (about 15°C) for them.