Baking pan size converter

A 9×13 pan has 117 square inches, an 8×8 has 64. Going from a 9×13 to an 8×8, multiply the recipe by 0.55. Pick both pans to see the scale and the bake time advice.

Free, no sign-up · Updated November 4, 2026

Pan in the recipe

WidthLength

Pan you have

WidthLength

Measured inDepth

Multiply the recipe by

—×

Recipe pan area: sq in
Your pan area: sq in
Recipe pan holds: cups
Your pan holds: cups
Batter to fill it: –cups

Pan areas

Baking area in square inches
Pan	Area	Volume at 2 in deep
9×13 inch	117	16.2 cups
8×8 inch	64	8.9 cups
9×9 inch	81	11.2 cups
11×7 inch	77	10.7 cups
10×15 inch jelly roll	150	20.8 cups
9 inch round	64	8.8 cups
8 inch round	50	7 cups
10 inch round	79	10.9 cups
6 inch round	28	3.9 cups

Rules that help

An 8 inch square and a 9 inch round are almost the same size. Swap them.
Fill a cake pan between half and two-thirds full.
If the new pan is more than about an inch bigger or smaller across, scale the recipe.
Chiffon, angel food and sponge cakes need their own pan.
Glass and ceramic heat more slowly than metal and brown less.

How it is calculated

Rectangle area = width × length. Round area = π × (diameter ÷ 2)².
Scale = new pan area ÷ old pan area. Same depth of batter.
Volume (cups) = area × depth ÷ 14.4375. Fill cake pans ½ to ⅔ full.

Worked example

9×13 to 8×8: 64 ÷ 117 = 0.55. Without scaling, the batter is 1.8 times as deep, so it needs 10 to 15 minutes longer. An 8 inch square and a 9 inch round are within 1% of each other: swap them freely.

Sources

King Arthur Baking, Why the size of your baking pan matters so much
Smaller pan: 10 to 15 minutes longer. Larger pan: start checking 10 to 15 minutes early. Fill ½ to ⅔ full. 8 inch square = 9 inch round, 8.8 cups at 2 inch deep.
King Arthur Baking, The essential alternative baking pan sizes
Pan areas: 8×8 is 64, 9×13 is 117, 9 inch round about 64, 8 inch round about 50 square inches.

Numbers checked November 4, 2026.

Questions

Can I bake a 9×13 recipe in an 8×8 pan?

Yes, but make about half the recipe (the scale is 0.55). If you use the full recipe, the batter is about 1.8 times as deep, so it will take longer and may not bake through in the middle. Fill the pan no more than two-thirds full.

Can I swap an 8 inch square pan and a 9 inch round pan?

Yes. King Arthur treats them as interchangeable: both hold about 8.8 cups at 2 inches deep.

How do I change the bake time?

King Arthur says a smaller pan may take 10 to 15 minutes longer, and a larger pan should be checked 10 to 15 minutes early. These are starting points. Use a toothpick or thermometer.

Do I change the oven temperature?

King Arthur gives no temperature change for a different pan size. Glass and ceramic pans heat more slowly and brown less than metal ones, so they can need a little more time.

Which cakes should not be moved to another pan?

Chiffon, angel food and sponge cakes need the height of their own pan to rise.

How full should I fill the pan?

For creamed and oil-based cakes, between half and two-thirds full.