Baking a 9x13 recipe in two 8-inch rounds instead? Here's the exact factor to scale the ingredients, and how the bake time shifts.
A 9x13 pan holds about 117 in²; two 8-inch rounds hold about 100 in² together. So multiply the recipe by about 0.86× to fill the rounds to the same depth. Bake at the same temperature and check a few minutes early.
Geometry is exact area math; temperature and time are directional guidance from baking practice, not formulas. Always test for doneness.
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.