Use this easy conversion formula to make cake recipes that call for a square or rectangular cake pan or sheet pan fit your square or rectangular cake pan of choice!
About a year ago I came up with a basic conversion formula for round cake pans to help you adapt baking recipes for different round cake pan sizes. And now I also came up with one for square or rectangular cake pans! Using this formula, you can easily calculate by which factor you need to multiply your ingredients to make your favorite recipe fit your pan of choice.
And the math involved is not hard! In fact, it’s super easy. Even I can do it 😉
Why you need this formula
Imagine being in your kitchen, ready to bake some brownies from a recipe you found on The Tough Cookie, because it’s your go-to blog for delicious recipes (right?). The first thing you do is turn on your oven and read through the recipe, like the sensible home baker that you are. Say, the recipe you want to make calls for an 8-inch x 8-inch square baking pan, and all you have is a 9-inch x 9-inch baking pan. Or, even worse, all you have is a 7-inch by 9-inch rectangular baking pan. What to do? Should you just make the recipe in the wrong-sized baking pan? Will it work?
And what if you want to double or triple a recipe you’ve tried before, but are unsure what pan to use? Again, should you wing it? Or should you do the math so that your brownies are exactly as thick, fudgy and delicious as if you’d baked them in the pan you’d normally use?
Of course, you want to make sure that you end up with something delicious, so you should definitely use my Cake Pan Conversion Formula for Square and Rectangular Pans!
The square or rectangular cake pan conversion formula in centimeters and inches
With this formula, you can adjust the original square/rectangular cake recipe to fit your square/rectangular cake pan of choice.
Step 1: determine the area (the surface of the cake pan bottom) of the pan the recipe calls for: