About this tool
Baking / Cake Pan Size Converter is a free, in-browser tool that tells you how to adjust a recipe when you swap one baking pan for another. Define your original pan and the pan you want to use — round, square or rectangular — and it compares their volumes and returns the factor to scale the recipe by. Everything is computed locally.
Each pan's volume is its base area times its height: a round pan is π × (diameter ÷ 2)² × height, a square pan is side² × height, and a rectangular pan is length × width × height. The recipe scale factor is the target volume divided by the original volume, so a factor of ×1.5 means the new pan holds half again as much batter. A fill tile also shows what percentage of the new pan the original recipe would fill if left unscaled.
Use the same unit (all inches or all centimetres) for every dimension — the factor is a ratio, so the units cancel out. Multiply each ingredient by the factor and keep the batter depth similar to your original for reliable baking times.