Toolman

25 cm / 10 in round vs 20 × 30 cm traybake

25 cm / 10 in round20 × 30 cm traybake
Size25 cm across20 × 30 cm
Base area490.9 cm²600 cm²
Usual depth5 cm5 cm
Holds2.45 L2.7 L

Can you swap them?

Scale the mixture, or accept a flatter cake. 20 × 30 cm traybake has 22.2% more area, so a 25 cm / 10 in round mixture poured straight in sits 82% as deep. It still bakes, and it browns more at the edges for being shallower. Multiplying by 1.22 restores the depth the recipe was written for.

Scaling the recipe

Recipe written forBaked inMultiply byOr leave it and get
25 cm / 10 in round20 × 30 cm traybake1.2282% of the depth
20 × 30 cm traybake25 cm / 10 in round0.82122% 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 82% as deep is done earlier, not cooler. Leave the temperature alone, start testing at about 82% 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 × 30 cm traybake instead of a 25 cm / 10 in round?

Yes, with the mixture multiplied by 1.22. 20 × 30 cm traybake has 600 cm² of base against 490.9 cm², so an unscaled 25 cm / 10 in round recipe sits 82% as deep and bakes faster.

What is the difference between a 25 cm / 10 in round and a 20 × 30 cm traybake?

25 cm / 10 in round has a base area of 490.9 cm² and 20 × 30 cm traybake has 600 cm² — 20 × 30 cm traybake is 22.2% larger. At their usual depths they hold 2.45 L and 2.7 L.

Do I need to change the baking time between a 25 cm / 10 in round and a 20 × 30 cm traybake?

Yes. Moving a 25 cm / 10 in round mixture into 20 × 30 cm traybake makes it 82% as deep, so start checking at about 82% of the stated time. Depth drives baking time far more than tin diameter does.

25 cm / 10 in round in full · 20 × 30 cm traybake in full · All tin comparisons · All baking tin sizes