Baking pan size converter
Pick the pan the recipe was written for and the pan you have. The tool compares their floor area and tells you by what factor to multiply the recipe, assuming the batter fills both to the same depth.
Runs in your browser: nothing you enter is sent anywhere.
How to use it
- Choose the shape of the pan in the recipe and enter its size.
- Choose the shape of the pan you will use and enter its size. Use the same unit (inches or centimetres) for both.
- Multiply every ingredient in the recipe by the factor shown. The recipe scaler does that for a pasted list.
How it works
The area of each pan is calculated and the multiplier is your pan’s area divided by the recipe pan’s area. The percentage line shows the same thing as a change: ×1.84 is +84%.
Worked example
A recipe is for a 9 inch round cake pan and you have a 9 × 13 inch rectangle. The round pan is π × 9² ÷ 4 = 63.6 square inches. The rectangle is 9 × 13 = 117 square inches. 117 ÷ 63.6 = ×1.84, so you need about 84% more batter.
The other way round, an 8 inch square recipe (64 square inches) in a 9 inch round (63.6) gives ×0.99: use the recipe as it is.
Tips
- Aim for a multiplier within about ±10% of 1 to keep the same depth and bake time; beyond that, expect to adjust the time.
- Fill pans to the same depth as the original recipe, not to the brim.
- The result is only as good as the measurement: check the real inside size of your pan.
Frequently asked questions
How is the multiplier worked out?
The tool divides the floor area of your pan by the floor area of the recipe pan. Round: π × diameter² ÷ 4. Square: side². Rectangle: length × width. A 9 inch round pan is 63.6 square inches and an 8 inch square pan is 64, so one can replace the other with almost no change.
Which units should I use?
Either inches or centimetres, but the same unit for both pans. The multiplier is a ratio and does not depend on the unit; the two area figures are in square inches or square centimetres to match what you typed.
Does the depth of the pan matter?
Yes. This tool assumes the batter will be at the same depth in both pans, as it works from the floor area only. A much deeper or shallower pan, or a pan with sloped sides, changes the depth of the batter, the baking time and the risk of overflow.
Do I need to change the baking time?
Possibly. A pan with more area gives a thinner layer that bakes faster, and a smaller pan a thicker one that takes longer. Start checking early and go by how the cake looks and feels, not just the timer. The tool does not predict times.
Is the pan size measured inside or outside?
Pan sizes are normally given as the inside dimensions at the top. If you only know the outside size, subtract the thickness of the rim on both sides for a better result.