20cm square tin to 18cm square tin
Multiply every ingredient by
×0.81
A 18cm square tin (7in) has 19% less area than a 20cm square tin (8in). Same depth of cake, less mixture.
| In the recipe | For your tin |
|---|---|
| 100g | 81g |
| 250g | 203g |
| 3 eggs | 2.4 eggs |
Paste your recipe into the scaler, already set to ×0.81. It rounds everything sensibly and tells you what to do with part of an egg.
The working
20cm square tin: 400cm² of base. 18cm square tin: 324cm². 324 ÷ 400 = 0.81. This assumes both tins are the same depth.