How pan conversion works
Two pans hold the same batter depth when they have the same surface area, so the fair comparison between pans is area, not diameter. A 9-inch round (about 64 in²) and an 8-inch square (64 in²) are nearly perfect substitutes; a 9-inch round and an 8-inch round differ by 27% — enough to matter.
This tool divides the area of your pan by the area of the recipe's pan and gives you a multiplier. Use it with our recipe scaler to adjust every ingredient at once. If the factor is between roughly 0.85 and 1.15, just use the recipe as written and watch the bake time.
Bake time tip: keep the oven temperature the same. Shallower batter bakes faster, deeper batter slower — start checking 10 minutes early either way.