You select a "from" pan and a "to" pan from the dropdown menus. The tool looks up each pan's cross-sectional area — using π·r² for round and Bundt pans, length × width for square and rectangular pans — then divides the new pan's area by the original to get a ratio. That ratio is your ingredient multiplier. It assumes both pans have similar depth; if the substitute is significantly shallower, you may need to reduce the recipe or use two pans.
Measure the inside dimensions (diameter for round, length × width for rectangular) and compute the area yourself. For round pans, area = π × (diameter ÷ 2)². For square or rectangular pans, area = length × width. Then divide your pan's area by the recipe pan's area to get the multiplier.
Usually, yes. A larger pan spreads batter thinner, so it bakes faster — check 5–10 minutes early. A smaller pan piles batter deeper, so it needs more time at a slightly lower temperature to cook through without burning the edges.
Absolutely — that is exactly what this tool is for. A 9-inch round (63.6 sq in) is very close to an 8-inch square (64 sq in), so those two are nearly interchangeable with almost no recipe adjustment.
Beat the eggs first, then measure by volume. One large egg is roughly 3 tablespoons. If you need 1.27 eggs, beat one egg and use about 3.8 tablespoons — close enough for most baking.
Estimate only. Results reflect your inputs and standard formulas. Double-check important decisions independently.