🍰 Baking

Cake Pan Converter

Choose the pan the recipe was written for and the pan you actually have, then press Calculate to get the batter scale factor.

Built by the UnitCalConv team · Last reviewed 2 November 2026 · Report an error

About the Cake Pan Converter

Pan swaps fail because volume scales with area, and area scales with the square of the width. Going from an 8-inch round to a 9-inch round is not 12.5% more batter, it is 26.6% more — which is why the same recipe sometimes overflows and sometimes comes out flat.

Keep the depth the same and scale the batter by the area ratio. If the new pan is much deeper or shallower, the baking time changes too: shallower bakes faster, deeper needs a lower temperature and a longer time.

How the calculation works

Round area = π × (diameter ÷ 2)²
Square area = side × side
Scale factor = new pan area ÷ original pan area

Reference values

Common cake pan conversions by area
From	To	Scale batter by
8 in round	9 in round	1.27×
9 in round	8 in round	0.79×
8 in square	9 in square	1.27×
8 in round	8 in square	1.03×
9 in round	9 in square	1.15×
2 × 8 in round	9 in round	0.63×

Worked examples

An 8 in round recipe in a 9 in round pan: 63.6 in² becomes 50.3 in² if you scale up by 1.27 — batter rises about a quarter higher.
Two 8 in rounds instead of one 9 in round needs 0.63 of the batter, not half.
An 8 in square holds 64 in², slightly more than an 8 in round at 50.3 in².

Getting the depth right

Area alone does not decide the bake. If the new pan is shallower, the batter spreads thinner and sets faster, so start checking ten minutes early. If it is deeper, drop the oven temperature by 10 °C and extend the time; a deep batter that browns before it sets will dome and crack.

Common mistakes

Comparing diameters instead of areas. A 9 in pan is 27% bigger than an 8 in, not 12.5%.
Scaling by volume when the pan is a different shape — fill it with water to check.
Changing both pan size and recipe type at once, which makes a failed bake impossible to diagnose.

A last check on the From table: 8 in round 9 in round sits at the base of the chart, and the rows above it step in the same proportion, so you can scale from that first row instead of reading every line. If a figure you were quoted falls between two rows, it is the To side that has been rounded, not the conversion itself.

Frequently asked questions

Can I use a 9-inch pan instead of 8-inch?

Yes, scale the batter up by 1.27 and expect a slightly shallower cake that bakes a little faster.

Does the same rule work for square pans?

Yes, the area rule applies to any shape; measure the actual internal dimensions.

How do I adapt the baking time?

Same depth means roughly the same time. For a shallower pan, start checking 10 minutes earlier.

Pan area and batter volume chart

Area decides how much batter a pan takes; depth decides how long it bakes. The multiplier column compares each pan with an 8 in round tin, which is the size most recipes are written for.

Cake pan areas and volumes
Pan	Internal area	Batter at 2 in deep	vs 8 in round
6 in round	182 cm2	0.9 L	0.56x
7 in round	248 cm2	1.3 L	0.77x
8 in round	324 cm2	1.6 L	1.00x
9 in round	410 cm2	2.1 L	1.27x
10 in round	507 cm2	2.6 L	1.56x
11 in round	613 cm2	3.1 L	1.89x
12 in round	730 cm2	3.7 L	2.25x
8 in square	413 cm2	2.1 L	1.27x
9 in square	523 cm2	2.7 L	1.61x
10 in square	645 cm2	3.3 L	1.99x

A 9 in round pan has 27 percent more area than an 8 in round, so the same batter bakes shallower and faster. A 9 in square has 62 percent more, which is close to one and a half batches — that is why square tins so often overflow when a recipe is scaled by diameter alone.