How to scale a recipe to a different pan

Compare the areas of the two pans and scale the recipe by the difference. The batter then sits as deep as the recipe intended, so it bakes much as the recipe describes.

Divide your pan's area by the recipe pan's area, and multiply the recipe by the result. 9-inch square to 9 × 13: × 1.44 8-inch round to 9-inch round: × 1.27

Scale to a new pan in three steps

  1. Measure both pans across the top, from inside edge to inside edge. Pans are often sold by their outside size.

  2. Find each area in the table below, or work it out: width × length, or 3.14 × half the width × half the width for a round pan.

  3. Divide your pan's area by the recipe's, round to the nearest quarter, and type it as the custom amount in the scaler.

Pan areas

Pan Area (sq in)
6-inch round 28.3
8-inch round 50.3
9-inch round 63.6
10-inch round 78.5
8-inch square 64
9-inch square 81
11 × 7-inch 77
9 × 13-inch 117
8½ × 4½-inch loaf 38.3
9 × 5-inch loaf 45

An 8-inch square (64 sq in) and a 9-inch round (63.6 sq in) hold almost exactly the same, so a recipe for one bakes in the other without changes.

Multipliers for common swaps

“Exact” is the ratio of the areas. “Scale by” is the nearest quarter, so the scaled amounts are exact cups and spoons rather than rounded ones; the batter ends up a few percent deeper or shallower.

Recipe's pan Your pan Exact Scale by
9-inch square 9 × 13-inch 1.44 1 ½×
8-inch square 9 × 13-inch 1.83 1 ¾×
8-inch square 9-inch square 1.27 1 ¼×
9-inch square 8-inch square 0.79 ¾×
8-inch round 9-inch round 1.27 1 ¼×
9-inch round 8-inch round 0.79 ¾×
Two 9-inch rounds 9 × 13-inch 0.92 As written
9 × 13-inch 9-inch square 0.69 ¾×
9 × 13-inch 8-inch square 0.55 ½×
8½ × 4½-inch loaf 9 × 5-inch loaf 1.18 1 ¼×

Example: brownies from a 9-inch square to a 9 × 13

The 9 × 13 is 1.44 times the area, so scale by 1 ½×:

9-inch square 9 × 13-inch
1/2 cup butter ¾ cup butter
1 cup sugar 1 ½ cups sugar
2 eggs 3 eggs
1 tsp vanilla extract 1 ½ tsp vanilla extract
1/3 cup cocoa powder ½ cup cocoa powder
1/2 cup all-purpose flour ¾ cup all-purpose flour
1/2 tsp salt ¾ tsp salt

Rounding 1.44 up to 1 ½× makes the batter about 4% deeper, so start checking at the recipe's time and allow a few minutes more.

Depth and baking time

Scaling by area keeps the batter's depth, and depth is what sets the baking time for cakes, bars and breads. If you put a whole recipe into a larger pan without scaling it, the batter is shallower and bakes faster; in a smaller pan it is deeper and takes longer. Either way, go by the recipe's sign of doneness rather than the clock.

Loaf, tube and Bundt pans are deep, so compare them by how much they hold: fill each with water, a cup at a time, and divide. Scaling a recipe down instead? The halving guide has the pans for a half batch.

Questions

How much bigger is a 9 × 13 than a 9 × 9 pan?

1.44 times the area: 117 square inches against 81. Scale a 9 × 9 recipe by 1 ½× to fill a 9 × 13.

Can I bake a 9 × 13 recipe in two 8-inch squares?

Yes. Two 8-inch squares are 128 square inches, close to the 9 × 13's 117, so the batter is just a little shallower. Check it a few minutes early.

Is a 9-inch round the same as an 8-inch square?

Nearly: 63.6 and 64 square inches. Swap them without changing the recipe.

Will a two-layer cake fit a 9 × 13?

Yes. Two 9-inch rounds are 127.2 square inches and a 9 × 13 is 117, so the batter is about 9% deeper. Bake it a little longer, checking from the recipe's time.

Sources

Amounts use US cups and spoons (1 cup = 16 tablespoons = 48 teaspoons). Checked against these sources on October 23, 2026.

More guides

All guides