Pan Size Converter
Convert baking recipes between different pan sizes and shapes. Get the exact scaling factor, adjusted ingredient amounts, and baking time so your cakes, brownies, and breads turn out perfectly in any pan you have on hand.
Quick Conversions
Click a common swap to auto-fill both pans.
From Pan (Original Recipe)
To Pan (Your Pan)
Volume Comparison
Tips for This Conversion
Common Pan Volumes Reference
| Pan | Dimensions | Volume (cups) |
|---|---|---|
| Round | 8" × 2" | 6 cups |
| Round | 9" × 2" | 8 cups |
| Round | 10" × 2" | 10.5 cups |
| Square | 8" × 2" | 8 cups |
| Square | 9" × 2" | 10 cups |
| Rectangle | 9×13" × 2" | 14 cups |
| Loaf | 9×5" × 3" | 8 cups |
| Loaf | 8.5×4.5" × 2.5" | 6 cups |
| Bundt | 10" × 3.5" | 12 cups |
| Springform | 9" × 3" | 10 cups |
| Muffin (12-cup) | Standard | 3.5 cups total |
How the Pan Size Converter Works
This pan size converter calculates the volume of your original pan and your target pan using standard geometric formulas. Round pans use the cylinder formula (pi times radius squared times height), while square and rectangular pans use length times width times height. The ratio between the two volumes gives you a precise scaling factor. Multiply every ingredient in your recipe by this factor and you will have the correct amounts for the new pan. The converter also adjusts baking time and temperature because pan size directly affects how heat reaches the center of your batter.
Switching between pan shapes is one of the most common baking challenges. A recipe written for a 9-inch round cake pan might need to work in an 8-inch square pan or a 9-by-13-inch rectangle. Without the correct volume adjustment, you risk overfilling a smaller pan (causing overflow) or underfilling a larger one (producing a thin, dry result). This tool eliminates the guesswork by giving you exact scaling factors and practical tips for every conversion.
Pan Size Conversions for Common Baking Swaps
The most frequently used pan conversion is 9-inch round to 8-inch square. These two pans have nearly identical volumes (about 8 cups each), making them almost perfectly interchangeable without any recipe adjustment. A 9-by-13-inch rectangular pan holds roughly the same volume as two 9-inch round pans, which is why layer cake recipes often translate directly to sheet cake form.
Bundt pans hold significantly more batter than standard round pans. A 10-inch Bundt pan holds about 12 cups, equivalent to roughly 1.5 times a 9-inch round. When scaling up to a Bundt, you typically need to increase the recipe by 50 percent and extend baking time by 15 to 25 minutes because the thick ring shape takes longer to bake through. Loaf pans present a similar challenge because their tall, narrow shape means longer baking at a slightly lower temperature for even doneness.
Adjusting Baking Time and Temperature
When you scale to a larger pan, the batter layer becomes thinner, which means it bakes faster. As a general rule, reduce baking time by about 10 to 15 percent when moving to a significantly larger pan. Conversely, a smaller pan produces a thicker batter layer that needs more time in the oven, so add 10 to 15 percent to the original time. Always start checking for doneness about 5 minutes before the adjusted time and use the toothpick test rather than relying solely on time.
Temperature adjustments are less common but important for extreme size changes. If you are scaling down to a much smaller pan (like mini loaf pans), consider lowering the oven temperature by 25 degrees Fahrenheit to prevent the outside from overbrowning before the center is done. For very large or deep pans like tube pans, the standard temperature usually works fine, but covering with foil partway through baking can prevent overbrowning on top while the center catches up.
Tips for Successful Pan Substitutions
Always fill pans only two-thirds full to allow room for rising. If your scaled recipe produces more batter than the new pan can safely hold, bake the extra in a small ramekin or muffin tin alongside the main pan. Grease and flour the pan thoroughly when switching shapes, especially with Bundt pans where intricate designs can trap batter. Glass and dark metal pans absorb more heat than light-colored aluminum, so reduce the oven temperature by 25 degrees when using these materials. Let your baked goods cool in the pan for the recommended time before turning out to prevent sticking or breaking, which is especially important when using an unfamiliar pan shape.
Frequently Asked Questions
Can I use a 9-inch round pan instead of an 8-inch square?
Yes, a 9-inch round pan and an 8-inch square pan have nearly identical volumes of about 8 cups each. You can swap them directly without changing ingredient amounts or baking time. This is the most common and easiest pan substitution in baking.
How do I convert a 9x13 rectangle recipe to round pans?
A 9x13-inch rectangular pan holds about 14 cups of batter, which is roughly equal to two 9-inch round pans (8 cups each). Divide the batter evenly between the two rounds. Keep the same oven temperature and start checking about 5 minutes earlier since the layers are thinner.
What happens if I use a pan that is too small?
If the pan is too small, the batter will be thicker than intended and may overflow in the oven. It will also take longer to bake through, and the outside may overbrown before the center is done. Always fill pans no more than two-thirds full and bake any excess in a separate small pan.
Do I need to change the oven temperature when switching pan sizes?
For most pan swaps within a similar size range, the temperature stays the same. However, if you are moving to a much smaller or deeper pan, lower the temperature by 25 degrees Fahrenheit. For glass or dark metal pans, also reduce by 25 degrees since they absorb more heat than light-colored aluminum.
How do I convert a round pan recipe to a Bundt pan?
A standard 10-inch Bundt pan holds about 12 cups, compared to 8 cups for a 9-inch round. You will need to increase your recipe by about 50 percent. Extend the baking time by 15 to 25 minutes and test with a long skewer since the center tube of a Bundt pan creates a thicker ring of batter.
Can I use this converter for any type of baked good?
Yes, this converter works for cakes, brownies, cornbread, quick breads, and most batter-based recipes. For yeast breads, the principles apply but proofing time may also need adjustment since a different pan shape affects how the dough rises. For pies and tarts, pan depth and shape matter more than volume alone.