Understanding Pan Size Conversions
Area vs. Volume
Pan conversions are based on baking area (for thin batters like brownies) or volume (for thicker batters like cake). Our calculator uses area for the most accurate results with typical recipes.
Baking Time Adjustments
When changing pan sizes, baking time changes too. Larger pans with thinner batter cook faster. Smaller pans with deeper batter need more time. Always test with a toothpick!
Common Pan Equivalents
Frequently Asked Questions
Can I substitute a round pan for a square pan?
Yes! An 8" square pan and a 9" round pan have nearly identical baking areas (64 sq in vs 63.6 sq in). They can be used interchangeably for most recipes without adjusting ingredients.
How do I adjust baking time for different pan sizes?
As a general rule, adjust baking time by 5-10 minutes per inch of size difference. Larger pans with thinner batter cook faster. Start checking 10-15 minutes before the estimated time, using a toothpick to test doneness.
Can I use two smaller pans instead of one large pan?
Yes! Two 9" round pans equal approximately one 9x13" rectangular pan. Divide the batter evenly and reduce baking time by 10-15 minutes since the layers will be thinner.
How full should I fill my pan?
For most cakes, fill pans 1/2 to 2/3 full to allow room for rising. Cheesecakes and dense cakes can go higher. Never fill more than 3/4 full or the batter may overflow. If you have extra batter, make cupcakes!