About the Baking Pan Size Converter
This baking pan size converter tells you how much to scale a recipe when you bake it in a different pan. Pick the pan the recipe was written for and the pan you have — from 6-inch rounds to 9×13 rectangles, jelly roll pans, half sheets and loaf pans, or enter custom sizes in inches or centimetres — and it compares their areas and gives a single multiplier for every ingredient.
Keeping batter at the same depth is what keeps baking time and texture the same, and depth depends on area, not on the number printed on the pan. A 9-inch round holds about 27% more than an 8-inch round, and a 9×13 pan holds roughly the batter of two 9-inch rounds. Scale the recipe by the factor shown (use the recipe scaler to do the arithmetic) and the batter will fill the new pan to the same level.
Assumes pans of similar depth, usually 2 inches. If you keep the recipe unchanged instead, a smaller pan makes a thicker layer that needs a lower temperature and more time, while a larger pan gives a thinner layer that bakes faster.
With the default inputs, the multiply recipe by is 0.55 ×. Change any value above to recalculate instantly.
How to use the baking pan size converter
- 1Choose the pan the recipe calls for, or a custom size.
- 2Choose the pan you want to use.
- 3For custom pans, enter the dimensions and pick inches or centimetres.
- 4Multiply every ingredient by the factor — the recipe scaler can do it for you.
- 5Bake at the same temperature and start checking a few minutes early.
Formula and method
The volume of batter a pan holds at a given depth is its base area times the depth, so for pans of the same depth the ratio of areas tells you how much to scale the recipe. Round pans use π × radius², and square or rectangular pans use length × width. Loaf and sheet pans use their nominal top dimensions.
Multiply every ingredient by the factor and the batter will reach the same depth in the new pan, so baking temperature and time stay close to the original. Pans with sloped sides, fluted tube and Bundt pans hold less than their top dimensions suggest; for those, compare volumes by filling each with water.
- A₀
- Area of the pan the recipe was written for
- A₁
- Area of the pan you will use
- d
- Diameter of a round pan
Worked examples
9×13 recipe in an 8×8 pan
A 9×13 pan is 117 sq in and an 8×8 is 64 sq in. 64 ÷ 117 = 0.55, so make just over half the recipe to keep the same depth.
8-inch round recipe in a 9-inch round
An 8-inch round has an area of 50.3 sq in and a 9-inch round 63.6 sq in, a factor of (9 ÷ 8)² = 1.27. Increase the recipe by about 27%.
Custom 20 cm round to a 23 × 33 cm tin
A 20 cm round covers about 314 cm² (48.7 sq in); a 23 × 33 cm tin covers 759 cm². The ratio is about 2.4, so make roughly two and a half times the recipe.
Frequently asked questions
How do I convert a 9x13 recipe to an 8x8 pan?+
A 9×13 pan has 117 sq in and an 8×8 has 64 sq in, so multiply the recipe by about 0.55 — roughly half. Halving the recipe exactly gives a slightly thinner layer that bakes a few minutes faster.
Is a 9-inch round the same as an 8-inch square?+
Almost. A 9-inch round is about 63.6 sq in and an 8-inch square is 64 sq in, so you can swap them without changing the recipe. Corners of a square pan may brown a little faster.
How many 8-inch rounds equal a 9x13 pan?+
About 2.3. A 9×13 pan is 117 sq in and an 8-inch round is 50.3 sq in, so two 8-inch rounds (100.5 sq in) fall a little short; two 9-inch rounds (127 sq in) are a closer match. A standard two-layer cake recipe fits a 9×13 pan well.
Do I change baking time when I change pan size?+
If you scale the recipe so the batter depth stays the same, time barely changes. If you keep the recipe and use a smaller pan, the layer is deeper and needs more time at a slightly lower temperature.
How full should a cake pan be?+
Fill cake pans about half to two-thirds full so the batter has room to rise. Overfilled pans can overflow or sink in the middle; use the leftover batter for cupcakes.