BAKING MEASURES / PAN SUBSTITUTION

Change the pan. Check the plan.

A pan swap starts with area, then needs a little baking judgment.

Measure the inside base

Use the diameter of a round pan, one side of a square, or the width and length of a rectangle. Measure inside the base, rather than across the outer rim. Use the same unit for both sets of pans.

Keep the same batter depth

Our converter compares total base area. This gives the recipe multiplier needed to keep the original batter depth. An 8-inch square has an area of 64 square inches; a 9-inch round has about 63.62. They are close in area, but their side height and material still need checking.

Count pans, not cake layers

Enter the number of pans filled by the original recipe and the number you will fill with the scaled mixture. A cake later cut into several layers is still one pan. Both sets must have enough height for the batter and its rise. Shaped tins, Bundt pans and loaf pans need separate capacity and recipe checks.

Keep ingredient units consistent

The recipe scaler multiplies your entered amounts, including fractions, and keeps their units. It does not know the weight of a cup of your ingredient. Do not round a partial egg to a whole egg automatically: follow your recipe’s advice for beating and measuring a portion.

Use the recipe to judge doneness

A multiplier cannot predict baking time. Pan material, oven behaviour, shape and recipe type all matter. Follow the recipe’s temperature guidance and check doneness. Very large changes can also affect mixing and leavening, even when the arithmetic is correct.

Further references: King Arthur Baking: alternative pan sizes, how to reduce a recipe.