Recipes are written for a specific pan, but the pan in your cupboard doesn't always match. The good news is that switching pans is mostly simple arithmetic: compare the areas of the two pans, scale the batter by the difference, and adjust the baking time.
Step 1: Compare the Pan Areas
For pans of the same depth, the amount of batter you need depends on the area of the bottom.
- Square or rectangular pans: length × width. A 9 × 13 inch pan is 117 square inches.
- Round pans: 3.14 × radius × radius. A 9 inch round has a radius of 4.5 inches, so its area is about 64 square inches.
Measure across the inside of the top edge, since that is how pans are sold.
Step 2: Scale the Batter
Divide the area of your pan by the area of the recipe's pan. That number is your scale factor. Moving a 9 × 13 recipe (117 sq in) into an 8 × 8 pan (64 sq in) gives 64 ÷ 117 = 0.55, so you would use about 55% of every ingredient.
| Recipe pan | Your pan | Multiply by |
|---|---|---|
| 9 × 13 inch | 8 × 8 inch | 0.55 |
| 9 × 13 inch | two 9 inch rounds | 1.09 |
| 8 × 8 inch | 9 × 9 inch | 1.27 |
| 9 inch round | 8 inch round | 0.79 |
| 8 × 8 inch | 9 × 13 inch | 1.83 |
The pan size converter does this for any two pans, including custom sizes, and can send the factor straight to the recipe converter to scale every ingredient.
Step 3: Adjust the Time and Temperature
If the batter sits at the same depth as in the original pan, the baking time stays close to the original. Problems come when the depth changes:
- Shallower batter (same amount in a bigger pan) bakes faster. Start checking 5 to 10 minutes early.
- Deeper batter (same amount in a smaller pan) takes longer and risks dry edges around a raw middle. Lower the oven by 25°F and allow extra time.
Always test with a toothpick or skewer in the centre rather than relying on the clock.
Eggs and Other Awkward Amounts
Scaling by 0.55 or 1.27 gives odd amounts, and eggs are the hardest. A large egg weighs about 50 grams without its shell, so beat the eggs together and weigh out what you need. For example, 0.55 × 2 eggs = 1.1 eggs, or about 55 grams of beaten egg. Our guide on halving recipes with eggs covers this in more detail.
Pans That Need Extra Care
- Glass and dark metal pans absorb more heat. Lower the oven by 25°F and check early.
- Bundt and tube pans bake from the centre as well as the edges, so they need less extra time than you might expect.
- Muffin tins: a batter that fills a 9 × 5 loaf pan makes about 12 standard muffins, baked at the same temperature for roughly 18 to 22 minutes.
Questions
Can I bake a 9 × 13 recipe in two 8 × 8 pans?
Yes. Two 8 × 8 pans hold about 128 square inches, slightly more than a 9 × 13 (117), so the layers will be a little thinner. Start checking 5 minutes early.
Does a bigger pan need a lower temperature?
Not usually. Keep the temperature the same and adjust the time. Lower the temperature by 25°F only when the batter will be much deeper than the original.
How full should I fill a cake pan?
About half to two-thirds full, leaving room for the cake to rise.
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