From a 9 × 13 to two round layers
Two 9-inch rounds hold about 9% more than a 9 × 13, so the recipe works as it is: the layers are a little thinner, so start checking 5 to 10 minutes early. For layers just as deep, make 1.09 times the recipe.
Two 8-inch rounds hold less (101 square inches), so they need 0.86 of the recipe or a few cupcakes on the side.
Pan areas
| Pan | Area | × from a 9 × 13 |
|---|---|---|
| 8-inch round | 50 in² | ×0.43 |
| 9-inch round | 64 in² | ×0.54 |
| 10-inch round | 79 in² | ×0.67 |
| 8 × 8 in square | 64 in² | ×0.55 |
| 9 × 9 in square | 81 in² | ×0.69 |
| 7 × 11 in | 77 in² | ×0.66 |
| 9 × 13 in | 117 in² | ×1.00 |
| 9 × 5 in loaf | 45 in² | ×0.38 |
Questions
How do I convert a recipe to a different pan size?
Compare the pans' areas and multiply every ingredient by yours divided by the recipe's. A round pan's area is π × radius², a square or rectangle's is width × length. An 8-inch round is 50 square inches and a 9-inch round is 64, so going from 8 to 9 takes 1.27 times the recipe. The batter then sits just as deep, so it bakes the way the recipe intended.
Do I need to change the baking time?
If you scale the recipe, the batter is the same depth, so keep the temperature and start checking about 5 minutes early. If you pour the recipe as it is into a different pan, a thinner layer bakes faster (check 5 to 10 minutes early) and a deeper one bakes slower. Test with a skewer either way.
How full should a cake pan be?
About half to two-thirds. Most cake batter fills a pan about halfway. Past two-thirds it can rise over the top, so Panful warns you and suggests baking the extra as cupcakes.
What's half of ¾ cup?
6 tablespoons, or ¼ cup + 2 tbsp. A cup is 16 tablespoons and a tablespoon is 3 teaspoons, so Panful turns every odd amount into the cups, spoons and teaspoons in a standard measuring set.
What do I do with part of an egg?
Beat the eggs together and weigh what you need: a large egg is about 50 g out of the shell. For 1⅔ eggs, beat 2 and use 83 g.
Does it convert cups to grams?
No, on purpose. Panful keeps your recipe's own units, so there are no guesses about how much a cup of your flour weighs. Grams stay grams, cups stay cups.