23 cm / 9 in round vs 30 cm / 12 in round
| 23 cm / 9 in round | 30 cm / 12 in round | |
|---|---|---|
| Size | 23 cm across | 30 cm across |
| Base area | 415.5 cm² | 706.9 cm² |
| Usual depth | 5 cm | 5 cm |
| Holds | 2.08 L | 3.53 L |
Can you swap them?
Scale the mixture, or accept a flatter cake. 30 cm / 12 in round has 70.1% more area, so a 23 cm / 9 in round mixture poured straight in sits 59% as deep. It still bakes, and it browns more at the edges for being shallower. Multiplying by 1.7 restores the depth the recipe was written for.
Scaling the recipe
| Recipe written for | Baked in | Multiply by | Or leave it and get |
|---|---|---|---|
| 23 cm / 9 in round | 30 cm / 12 in round | 1.7 | 59% of the depth |
| 30 cm / 12 in round | 23 cm / 9 in round | 0.59 | 170% 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 59% as deep is done earlier, not cooler. Leave the temperature alone, start testing at about 60% 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 30 cm / 12 in round instead of a 23 cm / 9 in round?
Yes, with the mixture multiplied by 1.7. 30 cm / 12 in round has 706.9 cm² of base against 415.5 cm², so an unscaled 23 cm / 9 in round recipe sits 59% as deep and bakes faster.
What is the difference between a 23 cm / 9 in round and a 30 cm / 12 in round?
23 cm / 9 in round has a base area of 415.5 cm² and 30 cm / 12 in round has 706.9 cm² — 30 cm / 12 in round is 70.1% larger. At their usual depths they hold 2.08 L and 3.53 L.
Do I need to change the baking time between a 23 cm / 9 in round and a 30 cm / 12 in round?
Yes. Moving a 23 cm / 9 in round mixture into 30 cm / 12 in round makes it 59% as deep, so start checking at about 60% of the stated time. Depth drives baking time far more than tin diameter does.
23 cm / 9 in round in full · 30 cm / 12 in round in full · All tin comparisons · All baking tin sizes