Change pan size
Scale your ingredients for the pan you have.
Use approximately
55%
of each ingredient
Multiply the original recipe by 0.547009× to keep the same intended batter depth.
Scales ingredients, not baking time, temperature or doneness.
How to measure your pan ↗Measuring and using the result
Why the same-depth assumption matters
At the same intended batter depth, the amount of batter scales with the area of a simple pan’s bottom. Compare internal bottom measurements so both inputs describe the usable space.
Rectangle area = length × width
Round area = π × (diameter ÷ 2)²
Recipe quantity factor = replacement area ÷ original area
A factor of 1.266× means approximately 1.266 times the original recipe quantity for the same depth. It does not mean “bake for 1.266 times as long.”
A worked round-pan example
An 8-inch round pan has an area of π × 4² = 50.265 square inches. A 9-inch round pan has an area of π × 4.5² = 63.617 square inches.
63.617… ÷ 50.265… = 81 ÷ 64 = 1.265625
Going in reverse changes the ratio: 64 ÷ 81 ≈ 0.790123. The original pan always belongs in the denominator. Use “swap” to check the direction without retyping.
When this simple geometry is not enough
Use this for simple round and rectangular pans with comparable straight sides. Tapered walls and rounded corners make area an approximation. Pan capacity, headroom, batter behavior, and the recipe’s limits still matter.
This tool does not handle Bundt, tube, loaf, springform, or other shaped or depth-sensitive substitutions. It does not predict bake time, temperature, doneness, or a successful result. A correct area factor cannot establish those outcomes.
Use the original recipe’s guidance and a trusted baking reference before making a substitution.
Sources and scope
- King Arthur Baking · Alternative baking pan sizesArea comparisons, batter-depth assumptions, and substitution cautions.
Source last checked 31 October 2026.