Baking pan size converter
Baking in a different pan than the recipe calls for? Enter both pans, round, square, rectangle, loaf or Bundt, in inches or centimeters. You get the area ratio and the number to multiply the recipe by, so the batter stays the same depth.
Example: a 9-inch round cake baked in a 13 × 9 pan. Change anything.
Baking time and temperature after a pan swap
Scaling by area keeps the batter about as deep as in the original pan, which is what keeps the baking time close. Time and temperature still need watching. Each point says where it comes from.
- Keep the depth of the food the same. When you change pans, aim for the same batter depth as the original. Source: K-State Research and Extension, Cooking Basics: Reducing a Recipe (MF3531, June 2020).
- Keep the oven temperature, except for glass or dark metal. In a glass pan or a dark metal pan, lower the oven by 25 °F to avoid over-browning. Source: K-State MF3531. King Arthur Baking's own test found that only truly black pans needed the lower temperature; with medium-dark pans, start checking 5 to 10 minutes early instead. Source: PJ Hamel, Baking cake in a dark pan, King Arthur Baking, 10 March 2017.
- Smaller batch, shorter time. When you bake a smaller amount, start checking at about half the original time and add time as needed. Source: K-State MF3531.
- Deeper batter bakes longer. If your pan is smaller than the area ratio suggests and the batter ends up deeper, expect a longer bake; the edges set before the center. Many bakers lower the oven by about 25 °F for very deep pans so the edges do not overbake. Rule of thumb, not from a tested source.
- Shallower batter bakes faster. In a larger pan with thinner batter, start checking 5 to 10 minutes before the shortest time in the recipe. Rule of thumb.
- Bundt and tube pans are sized by volume. Their capacity is usually stamped on the bottom; if not, count the cups of water it takes to fill it. Fill with batter to about two-thirds. Rule of thumb.
- Test for doneness, not the clock. A toothpick in the center should come out clean, and a cake should spring back when pressed. For meat, egg dishes and casseroles, use a food thermometer. Source: K-State MF3531 (food thermometer for end-point temperatures).
Common baking pan sizes and areas
Areas are calculated from the nominal inside top measurements printed on the pan. The last column is the multiplier for a recipe written for a 9-inch round.
| Pan | Area (in²) | Area (cm²) | Capacity to rim* | From a 9″ round |
|---|
* Capacity to the rim assumes straight sides and square corners, so real pans hold less. For example, the geometric figure for a 13 × 9 × 2-inch pan is 16.2 cups, while K-State Research and Extension (MF3531) lists that pan as holding 14 to 15 cups. Bundt capacities are the sizes the pans are sold by.
How the numbers are worked out
- Round: area = π × (diameter ÷ 2)². A 9-inch round is π × 4.5² = 63.6 in².
- Square and rectangle: area = length × width. A 13 × 9 pan is 117 in².
- Loaf: the top length × width. Loaf pans taper, so this compares like with like, not the exact batter volume.
- Multiplier = area of your pan ÷ area of the recipe pan. 117 ÷ 63.6 = ×1.84.
- Bundt or tube pan: compared by volume: capacity of your pan ÷ capacity of the recipe pan. A flat pan's capacity is area × depth ÷ 14.4375 in³ per US cup.
- Units: 1 in = 2.54 cm exactly, so 1 in² = 6.4516 cm². 1 US cup = 236.59 mL.
Cite this page
Portionary. “Baking Pan Size Converter.” Toolwoven, 2026, https://scale.kevanto.net/pan-size-converter. Accessed 19 Oct. 2026.
Calculations are geometry. Time and temperature advice is credited to K-State Research and Extension and King Arthur Baking where it comes from them; the rest is marked as a rule of thumb. Last reviewed 19 October 2026.