Cake Pan Conversion Calculator
Switch a recipe from one pan to another without guessing. Enter the pan you have and the pan you want, and this tool compares their batter volume to give a scale factor for every ingredient — plus a note on bake time.
Advanced
Fraction of the bounding cylinder a fluted ring pan actually holds. Bundt pans vary a lot — if yours lists a cup capacity, adjust this until the source/target volume matches it.
Formula & how it works
Each pan's batter volume is base area × batter depth. Base area is π × (diameter ÷ 2)² for round pans, side² for square, and length × width for rectangular.
A Bundt or tube pan is approximated as its bounding cylinder times a fill factor, since the centre tube and flutes remove volume. The scale factor is target volume ÷ source volume; multiply every ingredient by it.
Worked example
A recipe made for an 8-inch round pan at 2 inches of batter fills about 100 cubic inches, roughly 7 cups. Moving it to an 8-inch square pan (also 2 inches deep) gives 128 cubic inches, so the factor is 1.27 — you would use 1.27 times each ingredient. Going the other way, from 8-inch square down to 8-inch round, the factor is 0.79.
Getting a good conversion
Match the batter depth, not the pan height
Pans are rarely filled to the brim. Cakes usually rise best when the batter starts around half to two-thirds up the side, so enter the depth the batter actually reaches and use the same figure for both pans. If you fill a taller pan deeper, the scale factor grows accordingly — the tool respects whatever depths you enter.
Round versus square catches people out
A square pan has more area than a round pan of the same nominal size, so a straight swap leaves a round recipe short. That is why an 8-inch round to 8-inch square needs about 27% more batter. Comparing volume rather than the label on the pan avoids thin, under-filled cakes.
Bundt and tube pans are approximate
Fluted ring pans vary enormously, so the fill factor here is only a starting estimate. If your pan is sold by capacity — a 10-cup Bundt, for instance — adjust the fill factor until the volume shown matches that number, then trust the scale factor. Always leave headroom so the batter does not overflow the centre tube.