Baking Pan Substitutions: How to Use What You Have

You're halfway through mixing a batch of brownies when you realize — you don't have a 9x13 pan. All you've got is an 8x8 and a round cake pan. Now what?

Good news: you don't have to scrap the recipe. Baking pan substitutions are totally doable, as long as you adjust your recipe to match. Here's everything you need to know.

Why Pan Size Matters in Baking

When you change pan sizes, you're changing how deep the batter sits and how much surface area is exposed to heat. A shallower pan means faster baking. A deeper pan means slower baking. Get it wrong and you end up with overbaked edges and a raw center — or worse, overflow.

The key is matching the volume of batter to the pan as closely as possible, and adjusting your recipe by the right scale factor.

Common Baking Pan Substitutions

Here are some of the most common swaps home bakers make:

9x13 pan → two 9-inch round pans. A 9x13 pan holds about the same volume as two 9-inch round pans. This is actually the most common substitution for layer cakes — split the batter evenly between both rounds.

9x13 pan → 9x9 pan. A 9x9 pan is about 70% the size of a 9x13. Use roughly 70% of each ingredient, and start checking for doneness 10 minutes earlier since the batter will be slightly deeper.

8x8 pan → 9x9 pan. A 9x9 is about 27% larger than an 8x8. You'll need to scale your recipe up by about 1.27 — or just make the original recipe and have a slightly shallower bake with a shorter cook time.

9-inch round → 8-inch round. An 8-inch round is about 21% smaller than a 9-inch. Reduce ingredients slightly and check for doneness a few minutes early.

Always Adjust Your Baking Time

Switching pan sizes almost always means adjusting your bake time:

Smaller or deeper pan → add 10-15 minutes, check often.

Larger or shallower pan → reduce by 10-15 minutes, check early.

Never rely solely on the original recipe time when you've changed pans. Use a toothpick — if it comes out clean, you're done.

Skip the Math — Use the Calculator

Figuring out the exact scale factor between two pan sizes can get fiddly. That's why we built the Baking Pan Conversion Calculator — just select your original pan and your new pan, and it instantly tells you exactly how to adjust your recipe.

No math, no guessing. Just better baking. 🍋