Toolman

23 cm / 9 in round vs 20 cm / 8 in square

23 cm / 9 in round20 cm / 8 in square
Size23 cm across20 × 20 cm
Base area415.5 cm²400 cm²
Usual depth5 cm5 cm
Holds2.08 L2 L

Can you swap them?

Swap them freely. The areas are within 3.9% of each other, which is less than the variation between two tins of the same nominal size from different manufacturers. Use the recipe as written.

Scaling the recipe

Recipe written forBaked inMultiply byOr leave it and get
23 cm / 9 in round20 cm / 8 in square0.96104% of the depth
20 cm / 8 in square23 cm / 9 in round1.0496% 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

The depths work out the same here, so use the time as written. Why depth sets the time and diameter barely does →

Frequently asked questions

Can I use a 20 cm / 8 in square instead of a 23 cm / 9 in round?

Yes, with the mixture multiplied by 0.96. 20 cm / 8 in square has 400 cm² of base against 415.5 cm², so an unscaled 23 cm / 9 in round recipe sits 104% as deep and bakes faster.

What is the difference between a 23 cm / 9 in round and a 20 cm / 8 in square?

23 cm / 9 in round has a base area of 415.5 cm² and 20 cm / 8 in square has 400 cm² — 23 cm / 9 in round is 3.9% larger. At their usual depths they hold 2.08 L and 2 L.

Do I need to change the baking time between a 23 cm / 9 in round and a 20 cm / 8 in square?

No. The two areas are within 3.9%, so the batter sits at effectively the same depth and bakes in the same time.

23 cm / 9 in round in full · 20 cm / 8 in square in full · All tin comparisons · All baking tin sizes