Baking Pan Size Converter
Use the baking tin you have by comparing it with the recipe’s tin. Get an ingredient multiplier based on pan area, and check depth and capacity separately.
Runs in your browser — your input is not uploaded to ToolsNow.
- The batter will sit shallower, which usually means a shorter bake. Start checking early.
Pans close in area to your original
| Pan | Multiplier needed |
|---|---|
| 20 cm round | 1× — near-direct swap |
| 8 in round | 1.03× — near-direct swap |
| 9 × 5 in loaf | 0.92× |
| 18 cm round | 0.81× |
The multiplier is the ratio of the two pans' areas, because batter quantity follows area when the depth stays similar — a 23 cm round tin holds about 32% more than a 20 cm one, not 15% more. Capacity figures are the geometric volume of the box; real tins hold less, are normally filled between half and two thirds, and loaf tins in particular vary a great deal because their sides slope. Volume is never converted to weight here — that needs the density of the specific batter, which this tool has no way to know. Baking time does not scale with the multiplier. A deeper batter needs longer and often a slightly lower oven; a shallower one needs less. Treat the original time as a starting point and test for doneness early.
How to use
- Describe the pan the recipe wants. Pick a shape and enter the dimensions, or choose a common size from the presets.
- Describe the pan you have. Same again. Units can differ between the two if that is how they are labelled.
- Add depths if you have them. Optional but useful — it unlocks the capacity comparison and makes the depth warning meaningful.
- Use the multiplier. Multiply every ingredient by it. The recipe scaler on this site will do that across a whole ingredient list.
- Read the notes. Large changes, loaf tins and depth differences all get a specific warning, because none of them are handled by the multiplier alone.
Questions
Why does the multiplier use area rather than width?
Because batter fills a two-dimensional footprint. A 23 cm round tin is 15% wider than a 20 cm one but holds about 32% more, since area goes as the square of the radius. Scaling by width is the single most common tin-swapping mistake and it consistently underfills the larger tin.
Do I need to change the baking time?
Almost certainly, and not by the multiplier. Time follows the depth of the batter and the surface area far more than the total quantity. The same batter spread thinner bakes faster; the same batter piled deeper bakes slower and often needs a slightly lower oven so the outside does not darken before the centre sets. Treat the original time as a starting point and test early.
Why will it not convert volume to weight?
Because that needs the density of the specific batter, which varies enormously — an aerated sponge and a dense fruit cake of the same volume differ hugely in weight. Any tool that converts a tin’s capacity straight to grams of batter is inventing a number. Capacity here is reported in millilitres only.
Are the capacity figures the real usable volume?
No. They are the geometric volume of the shape — length × width × depth, or πr²× depth. Real tins hold less because their sides slope, and they are normally filled between half and two thirds so the batter has room to rise. The figure is for comparing two tins with each other, not for deciding how much batter to pour.
Why do loaf tins get a special warning?
Because they vary more than any other shape. Sides slope by different amounts, depths differ, and two tins sold as the same nominal size can hold noticeably different volumes. If a loaf recipe matters, measure the tin by filling it with water rather than trusting the label.
How large a change is too large?
There is no hard limit, but past roughly one and a half times or two thirds of the original area, the result stops being a simple scale-up. Chemical leavening, cooking time and heat penetration all stop behaving proportionally, and at that point splitting the batter across two tins of the original size is usually a better answer than one much larger one.
Published by ToolsNow. How tools and sources are checked · Report a problem