# Don’t Have the Right Cake Pan for the Job? This Cheat Sheet Can Help

Kendra Vaculin

I am not what anyone would call a math person, but I am a scrappy cook, which occasionally means I have to bust out the calculator (...app on my phone). Scaling recipes up and down requires some finagling, but if you keep your eyes on the prize, you can easily quadruple a salad for a party or translate a giant lasagna into a romantic dinner for two. Cooking is nice that way: With a little common sense and basic multiplication skills (again, or an app), almost any recipe can be modified to fit almost any scenario.

Baking, on the other hand, is a different story. Because your brownies and birthday cakes rely on chemical reactions and exact leavening agent measurements to succeed, scaling up or down or changing the pan size necessitates a bit more precision.

I spent years as an enthusiastic but poorly equipped home baker, amped to make blondies on a weeknight but without the exact right tools to do so. Until relatively recently I had no standing mixer, no teaspoon measure (lost it in a move, but two half teaspoons worked just as well!), and very few vessels to bake cakes and cookies in—but that didn’t stop me from producing quite a few carbs in my kitchen. To make sheet cakes effectively in my 8x8 Pyrex, I needed to have math on my side. Luckily, one simple rule set me up to be an adept any-pan-goes baker for life, and it's worth memorizing if you're in the same boat.

## The Math Part

The gist is this: Dividing the area of one pan by the area of another will give you your multiplier. Multiply all of the ingredients in your recipe by that magic number to modify it to fit the new vessel. When scaling down from a big pan to a smaller one, divide the area of the small pan by the area of the large pan. When going up from small pan to big, reverse the order and divide the area of the large pan by the area of the small one.

Need an example? If you’re trying to make a recipe for a snack cake that’s meant for a 9x9-inch square pan in a 13x9-inch pan instead, divide the area of the big 13x9 guy (117) by the area of the littler 9x9 (81). The result is 1.44, so you’ll need to multiply every ingredient in the cake recipe by 1.44—or 1.5, to make your life easier—to create your new measurements.

Don’t be afraid of rounding up or down! Because you’ll apply that same rounding to every ingredient in the recipe, you’ll end up with the same strawberry bars at the end, they just might be slightly taller or thinner than the original cookie based on the move. In the cheat sheet below, you’ll see the exact number to multiply by to scale your recipe up, as well as a rounded number in parentheses that will make for easier ingredient adjustments. Also, because the pans are of similar depths, the total cook time should be the same, but always check with a toothpick or look for the visual cues the recipe calls for—like “golden brown and bounces back when you press on it”—to be sure.

This math is easiest for rectangular and square pans, but this method works for any baking project in any size or shape pan. If you’re working with a round pan, find the area by using the formula πr² (i.e.,  3.14 x the radius of the pan squared), then divide as normal.

A note on partial ingredients: If you have a scale, it’s easy to determine ⅔ of a tablespoon or half of an egg by weight (for whole eggs, beat them first before measuring); if you do not have a scale or simply want to eyeball this, I won’t tell anyone, you will not die, and your lemon bars will turn out fine.

### Standard pan areas cheat sheet

13x9 = 117 square inches

9x9 = 81 square inches

8x8 = 64 square inches

Half sheet (aka 18x13) = 234 square inches

8-inch round = 50.24 square inches

9-inch round = 63.59 square inches

### Scale down

13x9 → 9x9: multiply by 0.69 (⅔)

13x9 → 8x8: multiply by 0.54 (½)

9x9 → 8x8: multiply by 0.79 (1, aka keep the recipe the same for a slightly taller bake, or use ⅔ for just scant)

9-inch round → 8-inch round: multiply by 0.79 (same as above)

### Scale up

8x8 → 9x9: multiply by 1.26 (1 ¼)

8x8 → 13x9: multiply by 1.82 (2)

9x9 → 13x9: multiply by 1.44 (1 ½)

13x9 → half sheet pan: multiply by 2

8-inch round → 9-inch round: multiply by 1.26 (1 ¼)

### Change shape

9-inch round → 9x9 square: multiply by 1.27 (1 ¼)

8-inch round → 8x8 square: multiply by 1.27 (1 ¼)

8x8 square → 8-inch round: multiply by 0.79 (1, aka keep the recipe the same for a slightly taller bake, or use ⅔ for just scant)

9x9 square → 9-inch round: multiply by 0.79 (same as above)

Originally Appeared on Epicurious