Cake Pan Conversion Calculator
Same batter, different pan, different depth.
Cake Pan Conversion Calculator
Batter multiplier = new pan volume / original pan volume; area and depth ratios show where the change comes from.
Calculated instantly
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What This Calculator Does
The Cake Pan Conversion Calculator compares the volume and area of two rectangular pans to give a batter multiplier. It separates the area change from the depth change, which is what determines whether a recipe fits, overflows, or bakes unevenly.
How It Works
Rectangular pan volume is length times width times depth. Dividing the new volume by the original volume gives the multiplier to apply to the batter quantity. The area ratio shows the change in the footprint, and the depth ratio shows the change in batter depth when the same volume is used. If the multiplier is above one, the new pan holds more; below one, it holds less.
Example
A 9 x 13 x 2 in pan has a volume of 234 cubic inches. An 8 x 8 x 2 in pan has 128 cubic inches. The multiplier is 128 / 234 = 0.547, so the original recipe makes about 1.83 times the batter the smaller pan holds. The area ratio is also 0.547 because the depth is unchanged.
Formula
length x width x depthnew volume / original volume(new length x new width) / (original length x original width)new depth / original depthReading the Results
Batter multiplier
Multiply the recipe by this number to fill the new pan to the same depth. A multiplier below one means the original recipe is too much for the new pan.
Area ratio
How the footprint changed. It drives the baking time because a larger area exposes more batter to the oven heat.
Depth ratio
How the batter depth changes if you use the same volume. More than about 1.3 can mean a longer bake and a domed top.
Sources and References
King Arthur Baking - Cake Pan Sizes and Conversions
Pan capacity and batter scaling
A test-kitchen reference for common pan sizes and approximate capacities.
USDA Food Safety and Inspection Service - Baking and Egg Safety
Safe baking and egg handling
General food safety guidance for batters containing eggs and dairy.
References identify the method or data behind this calculator. Where a standard or tariff changes, the current edition applies, and the assumptions stated above take precedence over a remembered figure.
Frequently Asked Questions
Can I just use the same batter in a different pan?
Only if the pan volume is close. A smaller pan makes a deeper cake that may overflow or stay raw in the centre. A larger pan makes a thin layer that bakes fast and can dry out. Compare volumes first, then adjust the batter and the time.
How do I convert a round pan?
Measure the inside diameter and calculate area as pi times radius squared. Volume is area times depth. This calculator uses rectangles, so for round pans calculate the two volumes separately and use their ratio as the multiplier.
Should I change the oven temperature?
Usually not for a modest size change. Keep the temperature and adjust the time, checking early. A much deeper batter benefits from a slightly lower temperature and a longer bake so the centre sets before the crust over-browns.
How full should a cake pan be?
About half to two thirds full is a safe range for most cakes. Leave room for rise and avoid filling to the rim. If the multiplier says the batter would fill the new pan more than about two thirds, bake the excess as cupcakes or scale the recipe down.
Does pan material change the result?
Yes. Dark metal pans brown faster, glass heats more slowly and retains heat, and light aluminium is more forgiving. Adjust the temperature by about 15 C (25 F) for dark pans and check earlier. The volume conversion does not account for material.