Cake Pan Size Converter

Your recipe wants an 8 inch round tin and the only one in your cupboard is a 9 inch square. This converter works out how much to scale every ingredient by, how much batter each tin actually holds, and roughly how the bake time shifts.

Quick answer: To convert between cake pan sizes, divide the area of the pan you own by the area of the pan in the recipe, then multiply every ingredient by the result. An 8 inch round holds about 50 square inches and a 9 inch round about 64, so going from 8 to 9 inch round means multiplying by 1.27.

How to Use It

• Pick the shape and size the recipe calls for on the left.
• Pick the tin you actually own on the right.
• Multiply every ingredient by the number in the pink band. A factor of 1.27 means 100 g of flour becomes 127 g.
• Add your original bake time if you want an estimated window to start checking.

Common Pan Swaps

• 8 inch round to 9 inch round: multiply by 1.27
• 8 inch round to 8 inch square: multiply by 1.27, since a square holds more than the circle inside it
• 9 inch round to a 9 by 13 inch pan: multiply by 1.84
• 8 inch square to a 9 by 13 inch pan: multiply by 1.83
• One 8 inch round to 12 cupcakes: multiply by 0.43

Bake Time Changes with Depth

Heat travels from the edges inward, so what really sets the timing is how deep the batter sits, not how wide the tin is. Spread the same cake batter into a wider, shallower tin and it can be done 10 minutes early. Pour it into a narrow, deep tin and the edges dry out before the middle sets. Keep the temperature the same, start testing early, and trust a skewer over a clock.

Cake Pan Sizes and Areas

Use this cake pan size chart to compare tins at a glance. The last column is the number to multiply a recipe by when it was written for an 8 inch round.

Pan	Area (sq in)	Area (cm²)	Multiply vs 8 inch round
8 inch round	50	324	1.00
9 inch round	64	410	1.27
10 inch round	79	507	1.56
8 inch square	64	413	1.27
9 inch square	81	523	1.61
9 by 13 inch rectangle	117	755	2.33
9 by 5 inch loaf	45	290	0.90

Loaf tins are much deeper than cake tins, so a loaf cake bakes longer even when the numbers match. Inch to centimetre figures use the exact 2.54 cm per inch listed in the NIST unit conversion guide.

Questions Bakers Ask

Can I use a glass dish instead of a metal tin?

Yes, but glass holds heat longer and browns the edges faster. Drop the oven by about 15 degrees Celsius or 25 Fahrenheit and keep the time the same.

How full should I fill the tin?

About two thirds. Any fuller and the batter climbs over the rim as it rises. The converter already assumes this, so the cup figures it shows are batter, not the brim capacity of the tin.

What size pan equals two 8 inch round pans?

A 9 by 13 inch pan is the closest single pan. Two 8 inch rounds hold about 100 square inches of batter and a 9 by 13 holds 117, so the batter sits slightly thinner and may be ready a little sooner. Keep the temperature the same and start checking early.

Do I change the oven temperature for a different pan size?

Usually not. Keep the temperature the same and adjust the time instead: shallow batter bakes faster and deep batter slower. For a very deep cake, lowering the oven by about 15°C (25°F) helps the middle set before the edges dry out.

Scaling the ingredients next? The recipe scaler rewrites a whole list for you. More at free baking tools.