Baking Pan Conversion
Free Baking Pan Conversion calculator with clear step-by-step results.
About Baking Pan Conversion
Rectangular pans are interchangeable by base area, not by side length. The ratio of new area to original area is the factor to multiply every ingredient by, and because batter depth changes inversely with area the bake time is adjusted by a fractional power of that depth ratio.
Formulas
Batter scale factor
Scale = (new length x new width) / (original length x original width)
Bake time
New time = original time x (1 / scale)^0.6
Worked example
With the default values below, Baking Pan Conversion returns Multiply the recipe by of 1.134. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Original pan lengthminimum 1 cm
- 23 cm
- Original pan widthminimum 1 cm
- 23 cm
- New pan lengthminimum 1 cm
- 20 cm
- New pan widthminimum 1 cm
- 30 cm
- Original bake timeminimum 1 min
- 35 min
Results
- Multiply the recipe by
- 1.134 x
- Original pan area
- 529.0 cm2
- New pan area
- 600.0 cm2
- Estimated bake time in the new pan
- 32 min
Step by step
- 1Values used
- 2Batter scale factor
- 3Bake time
- 4Multiply the recipe by= 1.134 x
- 5Original pan area= 529.0 cm2
- 6New pan area= 600.0 cm2
- 7Estimated bake time in the new pan= 32 min
Assumptions and limits
- The result is derived only from the 5 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 3 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
Can I keep the same oven temperature?
For a scale factor between about 0.7 and 1.4, yes. Beyond that, drop the temperature by 10-15 C for a deeper batter so the centre sets before the edges over-colour.
Why the 0.6 exponent on bake time?
Heat reaches the centre by conduction, so time scales with depth faster than linearly but slower than the square. An exponent near 0.6 matches observed times for cakes and brownies better than a straight ratio.