Baking Pan Size Converter

Swapping baking pans mid-recipe is fine as long as the volumes match. A 9-inch round pan (2 inches deep) holds about 7.07 cups, while a 9×13-inch rectangular pan holds about 14 cups. When the volumes are similar, bake time stays close; when they differ, bake time shifts with the batter depth.

The formula

Round pan:       volume (cu in) = π × (diameter/2)² × depth
Square pan:      volume (cu in) = side² × depth
Rectangular pan: volume (cu in) = width × length × depth

mL = cu in × 16.3871   (NIST: 1 cu in = 16.3871 mL)
US cups = mL ÷ 236.588

Practical examples

Example 1: Standard 9-inch round cake pan, 2 inches deep π × 4.5² × 2 = π × 20.25 × 2 ≈ 127.2 cu in → 2,085 mL → 8.82 cups

Example 2: 8-inch square pan, 2 inches deep 8 × 8 × 2 = 128 cu in × 16.387 = 2,097 mL → 8.87 cups — nearly identical to the 9-inch round

Example 3: 9×13-inch rectangular pan, 2 inches deep 9 × 13 × 2 = 234 cu in × 16.387 = 3,835 mL → 16.2 cups — about twice a 9-inch round

Common mistakes

Forgetting that depth matters as much as diameter. A 9-inch pan that is 3 inches deep holds 50% more batter than one that is 2 inches deep. Overfilling beyond ⅔ full causes overflow; underfilling produces thin results.

Treating round vs square pans as equivalent by diameter. A 9-inch square pan has a much larger area than a 9-inch round (81 vs 63.6 sq in). The square holds about 27% more volume.

Ignoring material and color. Darker pans absorb more heat and brown the exterior faster — lower your oven temperature by about 25°F (15°C) when switching from light to dark. Volume math handles quantity; temperature adjustment handles color.

International and regional variations

Quick reference