Measurements
Pan Size Converter
Get the area multiplier you need when moving a cake, brownie, or casserole recipe into a different pan.
Methodology
How we calculate this
Pan scaling compares usable surface area when batter depth is expected to stay similar.
The math
- Round pan area = π × radius²
- Rectangle or square area = length × width
- Scale factor = new pan area ÷ original pan area
Worked example
An 8-inch round is about 50.3 in² and a 9-inch round is about 63.6 in². 63.6 ÷ 50.3 = 1.26, so multiply each ingredient by about 1.26.
Frequently asked questions
Helpful answers
Can I bake brownies in a 9x13 pan instead of two 8-inch pans?
Compare the pans' usable areas, then multiply the batter by the area ratio. Keep the batter depth similar; a shallower layer usually bakes faster.
Can I use a 9-inch round pan instead of an 8-inch square pan?
Yes. Their areas are nearly identical, so the batter depth and baking time should be similar. Begin checking at the recipe's earliest stated time.
Can I substitute a loaf pan for a round cake pan?
Only if the batter leaves adequate headroom. A loaf pan makes a deeper cake, so the center usually needs more time even if the top looks done.
A practical starting point
Use the result as a planning estimate, then trust the ingredients, your thermometer, and the food in front of you. This tool is designed to make the first calculation easier—not to replace good kitchen judgment.
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