25 cm / 10 in round vs 20 cm / 8 in square
| 25 cm / 10 in round | 20 cm / 8 in square | |
|---|---|---|
| Size | 25 cm across | 20 × 20 cm |
| Base area | 490.9 cm² | 400 cm² |
| Usual depth | 5 cm | 5 cm |
| Holds | 2.45 L | 2 L |
Can you swap them?
Scale the mixture, or accept a flatter cake. 25 cm / 10 in round has 22.7% more area, so a 20 cm / 8 in square mixture poured straight in sits 81% as deep. It still bakes, and it browns more at the edges for being shallower. Multiplying by 1.23 restores the depth the recipe was written for.
Scaling the recipe
| Recipe written for | Baked in | Multiply by | Or leave it and get |
|---|---|---|---|
| 25 cm / 10 in round | 20 cm / 8 in square | 0.81 | 123% of the depth |
| 20 cm / 8 in square | 25 cm / 10 in round | 1.23 | 81% of the depth |
Multiply every ingredient, including the eggs — round to the nearest half egg and adjust the liquid rather than rounding a whole one up.
Baking time
A mixture 81% as deep is done earlier, not cooler. Leave the temperature alone, start testing at about 81% of the stated time, and let the skewer decide. Why depth sets the time and diameter barely does →
Frequently asked questions
Can I use a 20 cm / 8 in square instead of a 25 cm / 10 in round?
Yes, with the mixture multiplied by 0.81. 20 cm / 8 in square has 400 cm² of base against 490.9 cm², so an unscaled 25 cm / 10 in round recipe sits 123% as deep and bakes faster.
What is the difference between a 25 cm / 10 in round and a 20 cm / 8 in square?
25 cm / 10 in round has a base area of 490.9 cm² and 20 cm / 8 in square has 400 cm² — 25 cm / 10 in round is 22.7% larger. At their usual depths they hold 2.45 L and 2 L.
Do I need to change the baking time between a 25 cm / 10 in round and a 20 cm / 8 in square?
Yes. Moving a 20 cm / 8 in square mixture into 25 cm / 10 in round makes it 81% as deep, so start checking at about 81% of the stated time. Depth drives baking time far more than tin diameter does.
25 cm / 10 in round in full · 20 cm / 8 in square in full · All tin comparisons · All baking tin sizes