Food & baking · Cakes and bakes
Baking pan size converter.
Out of the pan the recipe calls for? Pick the pan it calls for and the pan you have, and see how the batter volume compares.
Inputs
Substitution
Enter both pans.
How to substitute baking pans
Compare the volume each pan holds to the brim: area times inside depth. A round pan has area pi x (diameter / 2)^2 and a rectangle has width x length. Divide your pan's volume by the recipe pan's volume to get the scaling factor, then multiply every ingredient by it.
Worked example. A recipe is for an 8 x 8 inch pan (64 sq in, 2 in deep, 128 cubic in). You have a 9 x 13 pan (117 sq in, 234 cubic in). The factor is 234 / 128 = 1.83, so almost double the batter fills it to the same depth. Fill batter pans only about half to two thirds full, since they rise.
Pan sizes are the inside size at the rim; measure your own, as pans labelled the same can vary by an inch. Bake time changes with batter depth: a thinner layer finishes sooner and a deeper one takes longer, so start checking early and go by a skewer or the recipe's doneness cues, not by the clock.
Frequently asked questions
Can I use a 9 x 13 pan instead of two 8 inch rounds?
Roughly, yes: two 8 inch rounds hold about 100 cubic inches each at 2 inches deep, and a 9 x 13 holds about 234. Check the factor here and expect a thinner cake that bakes sooner.
How do I convert a recipe from a 9 inch round to a 9 inch square?
A 9 inch square has more area (81 sq in vs 63.6), so the factor is about 1.27. Scale the recipe by that or accept a thinner bake.
How do I change baking time when I swap pans?
There is no exact rule. A shallower batter bakes faster, a deeper one slower. Start checking early and use a skewer or the doneness cue in the recipe.
Why does depth matter?
Volume is area times depth. Two pans with the same footprint but different depths hold different batter amounts.
Sources
Checked
- Geometry: area and volume of rectangles and circles (formula shown above). Pan depths (2 in for cake pans, 2.5 to 3 in for loaf pans) are typical assumptions, not measured values; check your own pan
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Scope
Volumes are to the brim and for comparison only. Batter fills a pan only part way, and bake times are not calculated.