Find the multiplier for a different cake pan
Compare the total base area of straight-sided round or rectangular pans. The result estimates how much batter you need to keep the original batter depth. It doesn't predict baking time.
Free, no account needed. Calculations run in your browser. Inputs are not saved; copy or download before leaving. Example values are illustrative.
Multiply ingredients by approximately 1.26563
1 × 8 diameter in round → 1 × 9 diameter in round Ingredient multiplier: 1.26563 Example: 200 g × 1.26563 ≈ 253.125 g Assumes the same batter depth and straight sides. Baking time must be checked separately.
The calculation and its limits
Round area = π × (diameter ÷ 2)². Rectangular area = width × length. Multiply by the number of pans, then divide your total area by the original total area. Inches convert to centimeters using 1 inch = 2.54 cm.
One 8-inch round pan to one 9-inch round pan gives 81 ÷ 64 = 1.265625. That is about 26.6% more batter to keep the same depth. Check that the new pan has sufficient height and the recipe's required headroom.
This model is unsuitable for Bundt, tube, tapered loaf, or shaped pans. Material, mixing capacity, and oven placement also affect baking. See Sally McKenney's pan-conversion guide for practical considerations. This tool doesn't claim to have tested your recipe.
Apply a ratio to ingredient quantities with the recipe scalerKeep the checked recipe with your notes
Record the quantities you used and what happened when you cooked them. A calculated variation still needs a cook-through before it becomes a recommendation.
Test your recipe in the new pan