Baking · pan swap

Two 8-inch round to 9x13 pan

Turning a two-layer cake recipe into a single 9x13 sheet? Here's the factor.

In short

Two 8-inch rounds hold about 100 in²; a 9x13 holds 117 in². Multiply the recipe by about 1.16× to fill the 9x13 to the same depth, and bake at the same temperature, checking a touch later.

Convert pans

Conversion
Scale ingredients1.16×
From area
To area
Time

Geometry is exact area math; temperature and time are directional guidance from baking practice, not formulas. Always test for doneness.

About this conversion

The ingredient scale factor is exact area math. Bake time follows batter depth, not volume — so we give the direction to adjust and a doneness cue rather than a fabricated time. Switch to “keep same batter” if you're not scaling the recipe, just using a different pan.

Converting different pans? Use the full pan size converter.

Can I bake a layer-cake recipe in a 9x13?
Yes — scale it up about 1.16× to fill the larger pan to the same depth, or accept a thinner sheet. Watch for slightly longer bake time.

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