Baking Pan Size Converter
Compare two baking pans by area and volume so you know how to scale a recipe.
Original pan (the one the recipe is written for)
New pan (the one you want to use)
Runs entirely in your browser. Nothing you type is uploaded anywhere.
How to use this tool
This cake pan size converter helps you swap one baking pan for another without ruining a recipe. First pick whether you measure in inches or centimeters. Then describe the original pan the recipe was written for: choose its shape and type in its size. Do the same for the new pan you actually want to use. The height fields are optional, but adding them lets the tool compare full pan volume instead of just the base area. Press Convert and you will see the area of each pan, the volume if heights were given, and a single scale factor you can multiply your ingredient amounts by.
The formula and how it works
Square or rectangular area = length x width
Pan volume = base area x pan height
Scale factor = new pan capacity / original pan capacity
Pans hold batter in proportion to their base area, so the most reliable way to scale a recipe is to compare areas. A round pan uses the circle formula, while square and rectangular pans simply multiply their two sides. If you provide a height for both pans, the tool compares volume (area times height) instead, which matters when one pan is much deeper than the other. The scale factor is the ratio of new capacity to original capacity: a factor of 1.5 means the new pan is half again as large, so you multiply every ingredient by 1.5. A factor below 1 means the new pan is smaller and you should reduce the recipe.
A real example
Say a recipe calls for a 9 inch round pan and you only own an 8 inch round pan. The 9 inch pan has an area of pi x 4.5 x 4.5, which is about 63.6 square inches. The 8 inch pan has an area of pi x 4 x 4, about 50.3 square inches. The scale factor is 50.3 divided by 63.6, which is roughly 0.79. So you would use about 79 percent of the original batter, or reduce each ingredient to four fifths. The leftover batter could go into a few cupcakes so nothing is wasted.
Common questions
Should I compare pan area or volume?
For most cakes and brownies, base area is the better guide because batter depth stays similar. Use volume comparison only when the two pans have clearly different heights, such as swapping a shallow sheet pan for a tall springform.
Do I need to change the baking time after scaling?
Often yes. A wider, shallower pan bakes faster, while a deeper or smaller pan bakes slower. Start checking a few minutes early and use a toothpick to test doneness instead of relying only on the original time.
Can I convert between round and square pans?
Yes. The tool reduces every pan to its area or volume, so it can compare a round pan to a square or rectangular one directly. A common rule of thumb is that a square pan holds a bit more batter than a round pan of the same width.
Why is the height field optional?
Many recipes only specify a pan width, and base area alone gives a good scale factor for typical batters. Add heights when you want the more precise volume ratio between two pans of different depths.
Is the result exact?
It is a close estimate meant for home baking, not professional measurement. Pan walls are slightly sloped and batters rise differently, so treat the scale factor as a strong starting point and adjust to taste. This is for educational use, not professional advice.