How do I convert a 9 x 13 recipe to two round pans?

A 9 x 13 pan holds about 14 to 15 cups, close to two 9-inch round pans at about 8 cups each. Split the batter evenly and start checking about 10 minutes earlier.

Recipe Scaler & Pan Size Converter

Halve it, double it, or move it to a different pan — get the exact multiplier instead of kitchen guesswork.

By Jamal, EasyCalcHub · Last updated July 2026

Ad space (banner)

Scale a recipe

Recipe makes (servings)

I want (servings)

Optional: paste ingredient lines (one per line, e.g. "1 1/2 cups flour")

1.5×

Multiply every ingredient by 1.5

Scaled ingredients

Convert between pan sizes

Recipe's pan

Diameter (inches)

Your pan

Side (inches)

1.01×

Your pan holds about the same — use the recipe as written

Quick answer

To scale a recipe, divide the servings you want by the servings the recipe makes — that's your multiplier for every ingredient. To convert between pans, compare their surface areas: a 9-inch round pan (≈64 sq in) and an 8-inch square pan (64 sq in) hold almost exactly the same batter, so most recipes swap between them with no change.

Cake pan volume chart

Approximate capacity when filled to the brim (pans are normally filled ½ to ⅔ full). Depths assume standard 2-inch-deep pans unless noted. Actual capacity varies by brand.
Pan	Approx. volume	Closest swap
6-inch round × 2 in	4 cups	Two-thirds of an 8-inch round
8-inch round × 2 in	6 cups	9-inch pie plate
9-inch round × 2 in	8 cups	8-inch square
10-inch round × 2 in	10–11 cups	9-inch square
8-inch square × 2 in	8 cups	9-inch round
9-inch square × 2 in	10 cups	10-inch round
9 × 13 inch rectangle	14–15 cups	Two 9-inch rounds
Loaf 8½ × 4½ in	6 cups	8-inch round
Loaf 9 × 5 in	8 cups	9-inch round
10-inch Bundt	12 cups	9 × 13 (slightly less)
9-inch springform	10 cups	9-inch square
Jelly roll 10 × 15 in	10 cups	9-inch square
Standard muffin cup	½ cup each	12 muffins ≈ one 9-inch round

How pan conversion works

When two pans have the same depth, what matters is the surface area of their bases. The converter uses these formulas:

Round pan area = π × (diameter ÷ 2)² · Square/rectangular pan area = length × width · Multiplier = your pan's area ÷ the recipe pan's area.

Example: a recipe for a 9-inch round pan (area ≈ 63.6 sq in) moved to a 9 × 13 pan (117 sq in) needs 117 ÷ 63.6 ≈ 1.8× the ingredients for the same cake height.

Adjusting bake time when you change pans

Keep the oven temperature the same, but expect the time to shift: a wider, shallower layer of batter bakes faster, while a deeper layer bakes slower. Start checking around 10 minutes earlier than the recipe says for shallower batter, and add gentle 5-minute checks for deeper batter. The cake is done when a skewer comes out clean, whatever the clock says.

What doesn't scale perfectly

Most ingredients scale in a straight line, but a few behave differently in large jumps: leavening (baking powder/soda), salt, and strong spices are often slightly reduced when you triple a recipe or more, and eggs come in whole units — round to the nearest half egg (beat one and use half). For doubling or halving, straight multiplication works fine.

Frequently asked questions

Can I use an 8-inch square pan instead of a 9-inch round?

Yes — this is the classic like-for-like swap. A 9-inch round pan holds about 8 cups and an 8-inch square pan also holds about 8 cups, so the recipe needs no adjustment. Bake time stays roughly the same; check a few minutes early.

How do I halve a recipe that uses 3 eggs?

Use 1½ eggs: crack and beat one egg, then measure out half (about 2 tablespoons) and add it with one whole egg. For most home baking this is accurate enough.

How do I convert a 9 × 13 recipe to two round pans?

A 9 × 13 pan (about 14–15 cups) is very close to two 9-inch round pans (about 8 cups each). Split the batter evenly between the two rounds and start checking for doneness about 10 minutes earlier.

Do I change the oven temperature when I change pan size?

Usually no — keep the temperature and adjust the time instead. The one common exception is dark or glass pans, which brown faster; many bakers drop the temperature by 25°F for those.

Why is my scaled-up cake dense in the middle?

Very large batches in deep pans bake unevenly: the edges set long before the centre. It usually works better to divide a big batch across two pans than to use one very deep one.

Ad space (banner)

Disclaimer: These conversions are provided for general information and home cooking only, "as is" and without warranty of any kind. Pan capacities and baking behaviour vary by brand, material, oven and altitude, so results may vary and all figures are approximate. Verify independently for any commercial, nutritional or allergen-sensitive use. See our full Disclaimer.

Related tool

Working from a US recipe with a kitchen scale? Use our Cups to Grams Converter to weigh each ingredient exactly.