Baking Pan Converter
Show the math
What Your Result Means
- Area Ratio: How much larger or smaller your substitute pan is compared to the original. A ratio of 1.27x means the new pan has 27% more surface area and needs 27% more batter.
- Batter Multiplier: The factor to apply to every ingredient in your recipe. Multiply each amount — flour, sugar, eggs, butter, liquid — by this number to fill the new pan to the same depth.
- Temp and Time Tip: When the batter layer gets noticeably thicker, reduce oven temperature by about 25°F and extend baking time. Thinner layers may bake faster — start checking a few minutes early.
How This Calculator Works
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.
Quick Questions
What if my pan is not listed?
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.
Do I need to adjust baking time?
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.
Can I swap a round pan for a square one?
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.
How do I scale eggs when the multiplier is not a whole number?
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.
Sources
- King Arthur Baking — Pan Size Substitution Guide (pan area chart and conversion tips)
- Wikipedia — Baking (general baking science and terminology)
Method & review
Estimate only. Results reflect your inputs and standard formulas. Double-check important decisions independently.