Methods & worked examples
Baking Pan Ratio Calculator — Methods & worked examples
How it works
Round base area = π × radius²; rectangular base area = base length × base width. Ingredient multiplier = new single-pan base area × new pan count ÷ (original single-pan base area × original pan count). Measure the inside base, excluding rims, handles and wall thickness. The rectangular width is not the wall height.
Worked examples
Changing two 20 cm round pans to three 15 cm round pans gives (3 × 15²) ÷ (2 × 20²) = 0.84375. Ingredients of 200, 160 and 120 g become 168.75, 135 and 101.25 g. A diameter reduced to 75% gives 56.25% of the area; including the change from two pans to three produces 84.375% of the total amount.
Scope & limitations
Equal batter depth and sufficient new pan height are required. Hollow, irregular or strongly tapered pans do not fit this simplified model. Materials and shapes affect heat transfer. The tool multiplies ingredient weights only; it does not convert oven temperature, baking time, doneness or food-safety requirements, and cannot validate an arbitrary recipe.
Method sources
Our original explanations and calculators use the methods above. This site is not affiliated with the cited brands or organizations.