Baking Pan Size Converter
Scale a recipe between pan sizes and shapes by comparing areas.
Compares base area at a similar depth. Keep the oven temperature and adjust the time — wider bakes cook faster, deeper ones slower.
Swapping pans without ruining the recipe
A recipe is sized to a particular pan. Use a different one and the batter depth — and the bake — change. The fix is to scale the ingredients by how much the pan’s base area changes.
scale factor = new pan area ÷ original pan area
Round areas use π × radius²; squares and rectangles are length × width. Multiply every ingredient by the resulting factor to keep the same depth, then adjust only the time — a shallower spread bakes faster.
A 20 cm round pan has an area of about 314 cm²; a 20 cm square pan is 400 cm². Moving from round to square is a scale factor of roughly 1.27 — multiply each ingredient by 1.27 and watch the bake time.
Keeping bakes reliable
Scaling by area keeps the depth — and therefore the texture and timing — close to the original. The number is the easy part; the judgement is in the oven, so lean on doneness cues rather than the clock when the shape changes a lot.
Baker’s notes
- Same depth, scaled batter. Area scaling assumes you fill to a similar depth.
- Temperature stays. Adjust the time, not the heat, in most cases.
- Test for doneness. A skewer or gentle press beats trusting the timer alone.