Cake Pan Converter
Moving a recipe to a different cake pan? Get the batter scale factor from the pans’ areas.
How it works
scale factor = new pan area ÷ original pan area (round area = π × radius²)
If the batter sits at the same depth, a cake bakes the same — so pans convert by bottom area. Multiply every ingredient by the area ratio. This assumes pans of similar depth (standard rounds and rectangles are about 2 inches); the loaf pan is included for quick breads, where the same logic holds.
Worked example
A 9-inch round recipe (63.6 sq in) headed into a 9 × 13 (117 sq in): 117 ÷ 63.6 = ×1.84 batter. That’s why a two-layer 9-inch cake recipe (2 × 63.6 = 127 sq in) fits a 9 × 13 almost exactly.
Frequently asked questions
How do I scale 1.84 eggs?
Whisk the eggs and weigh them — a large egg is about 50 g out of the shell, so 2 eggs × 1.84 ≈ 184 g, call it 3 large eggs plus 2 tablespoons of whisked egg. Weight beats fractions of a shell every time.
What about bundt and springform pans?
Bundts vary too much in shape for area math — convert by volume instead: fill each pan with measured water and compare cups. A 9-inch springform behaves like a deep 9-inch round (63.6 sq in).
Same pan size but different depth — does it matter?
Yes: the area math says ×1, but deeper batter needs a longer, gentler bake. Keep the recipe amounts, drop the temperature 25°F, and test with a skewer past the original time.
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This calculator is for educational purposes. Double-check important results before acting on them.