Only have a 9×13 when the recipe calls for two 8-inch rounds? Pick the pan the recipe uses and the pan you own. The converter compares their volumes and tells you how much to scale the batter and what to watch for.
Recipe pan holds-
Your pan holds-
Scale the batter-
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How it compares pans
The calculator works out the volume of each pan from its shape and size, then compares them. A difference under 10 percent can be ignored; bigger differences mean scaling the batter or expecting a thinner or thicker bake.
Baking time changes
A thinner layer bakes faster and a deeper one slower. Start checking 5 to 10 minutes early when you move to a larger pan, and add time in small steps for a smaller one.