Can I use a 9x13 pan instead of two 9-inch round pans?

Two 9-inch round pans hold about 254 cubic inches of batter combined, while a standard 9x13 sheet pan holds 234. That is roughly 8% less capacity, so the batter bakes slightly thicker. Most layer-cake recipes work in a 9x13 with one or two extra minutes in the oven, and the result is a single sheet cake instead of two layers.

How do I scale a recipe when the pan is bigger?

Divide the new pan's volume by the original pan's volume to get the batter multiplier, then multiply every ingredient by that number. A 9-inch round holds about 127 cubic inches and a 9x13 sheet holds 234, so the multiplier is roughly 1.84. Round to a sensible fraction such as 1.5x or 2x so weights stay easy to measure.

Do I need to adjust bake time when changing pan size?

Usually yes. A shallower pan finishes 5 to 10 minutes earlier and benefits from a slightly cooler oven (about 10°F or 5°C lower) so the edges do not over-bake. A deeper pan needs 5 to 15 extra minutes; tent the top with foil if it browns before the centre is set. Check the cake with a skewer near the new bake time.

How do I convert metric pan sizes to inches?

Divide centimetres by 2.54 to convert pan dimensions to inches. A 23 cm round is the same as a 9-inch round (the most common UK and EU size), and a 20 cm round is roughly an 8-inch round. Pan depth is usually labelled in centimetres too: 5 cm is about 2 inches, which matches the standard US cake pan depth.

Why does my batter spill over the edge of the pan?

The pan is too small for the recipe. Most cake recipes assume the batter fills the pan halfway to two-thirds, leaving room for the cake to rise. Pick a pan with at least 50% more volume than the original, or scale the recipe down with the batter multiplier and pour any leftover batter into a second pan of similar depth.

Pan Size Converter

Your recipe calls for one pan and your cupboard has another. Pan dimensions translate to batter volume, and the difference between a 9-inch round and a 9-inch square is enough to change how the cake bakes. Pick the pan the recipe calls for and see which of the common cake pan sizes hold the same amount of batter, plus how to scale the recipe and adjust the bake time. The calculator covers round, square, rectangle, loaf, bundt, springform, and tube pans:

Swapping a 9-inch round for an 8-inch square: the volumes are within 1%, so the swap works with no recipe change.
Cake batter left over: the source pan was too small; look for a bigger equivalent or scale the recipe down with the batter multiplier.
Scaling up to a sheet pan: a 9x13 sheet holds nearly twice the batter of a 9-inch round, so the recipe needs to roughly double.
Bundt vs tube pans: pick by cup capacity, not diameter; a 10-inch bundt holds about 12 cups and is closest to a 10-inch tube pan.
Metric pans: divide centimetres by 2.54 to get inches, then use the calculator the same way.

How the Pan Size Converter Works

Volume is the only thing the batter cares about. Two pans with the same internal volume hold the same amount of batter regardless of shape. A 9-inch round (about 127 cubic inches) sits within a percent of an 8-inch square (128 cubic inches), which is why the two swap so cleanly in cake recipes. A 9x13 sheet holds 234 cubic inches, almost twice the round, so a single recipe poured into it would bake thin and dry. The batter multiplier shown next to each equivalent scales the recipe up or down so the depth in the new pan matches the depth the recipe was designed for.

Bake Time and Temperature

Depth matters more than diameter for bake time. A shallower pan finishes earlier and benefits from a slightly lower oven temperature so the edges do not set before the centre. A deeper pan needs longer in the oven and a foil tent if the top browns before the inside is cooked. The advisory beside each pan flags both cases so you can adjust without guessing, and the calculator also warns when the volume difference is large enough to change the texture of the bake.

Pan Shapes and Their Uses

Round

Also known as: round cake tin, round cake pan, layer cake pan, sandwich tin
Common use: Layer cakes stacked with a filling. Most UK recipes bake a Victoria sponge in a pair of 20 cm sandwich tins, and the two layers are ready in about 25 minutes.

Square

Also known as: square cake tin, square cake pan, brownie tin, brownie pan, 8x8 pan
Common use: Brownies and flapjacks. Scottish tablet sets in a greased square tin too. It is boiled, not baked, so use the volume match and ignore the bake-time advice.
Fun fact: Corner pieces take heat from two sides and bake chewier than the middle. The Baker's Edge pan, launched in 2006, has inner walls that give every brownie at least two edges.

Rectangle

Also known as: 9x13 pan, 13x9 pan, sheet cake pan, traybake tin, oblong tin
Common use: Sheet cakes and traybakes, iced and cut while still in the tin. Some 9x13 pans come with a snap-on lid for taking the cake to a party in the tin it baked in.
Fun fact: A bakery quarter sheet pan has close to the same 9 by 13 inch base but 1-inch sides, so it holds about half the batter of a 2-inch-deep 9x13.

Loaf

Also known as: loaf tin, loaf pan, bread tin, 1 lb loaf tin, 2 lb loaf tin
Common use: Banana bread, pound cake and fruit loaves. The crust sets first and the centre keeps rising, which is why a loaf splits down the middle.
Fun fact: UK shops label loaf tins 1 lb or 2 lb after the weight of dough they take, and two brands' 2 lb tins can hold noticeably different amounts.

Bundt

Also known as: ring mould, ring tin, fluted ring cake pan, fluted tube pan, gugelhupf mould
Common use: Heavy batters such as sour cream cake or rum cake. The centre tube lets heat in from the middle, so the cake bakes through where a solid tin of the same volume would stay raw in the centre.
Fun fact: Bundt is a Nordic Ware brand name, made by adding a t to the German bund so it could be trademarked.

Springform

Also known as: springform tin, springform pan, spring form cake tin, cheesecake pan
Common use: Cheesecakes and chilled tortes that would crack if turned out. Run a knife around the edge, release the clasp and the side lifts off, leaving the cake on the base.
Fun fact: German brands such as Kaiser and Dr. Oetker sell springforms with a spare base that has a tube in the middle, turning the tin into a ring mould for gugelhupf.

Tube

Also known as: angel food cake pan, angel food pan, angel cake tin, chiffon cake pan
Common use: Angel food and chiffon cakes. The tin is left ungreased so the egg-white foam can grip the wall and climb, and the cake cools upside down on the tube.

Frequently Asked Questions

Can I use a 9x13 pan instead of two 9-inch round pans?: Two 9-inch round pans hold about 254 cubic inches of batter combined, while a standard 9x13 sheet pan holds 234. That is roughly 8% less capacity, so the batter bakes slightly thicker. Most layer-cake recipes work in a 9x13 with one or two extra minutes in the oven, and the result is a single sheet cake instead of two layers. Open plain flour converter
How do I scale a recipe when the pan is bigger?: Divide the new pan's volume by the original pan's volume to get the batter multiplier, then multiply every ingredient by that number. A 9-inch round holds about 127 cubic inches and a 9x13 sheet holds 234, so the multiplier is roughly 1.84. Round to a sensible fraction such as 1.5x or 2x so weights stay easy to measure. Open sugar converter
Do I need to adjust bake time when changing pan size?: Usually yes. A shallower pan finishes 5 to 10 minutes earlier and benefits from a slightly cooler oven (about 10°F or 5°C lower) so the edges do not over-bake. A deeper pan needs 5 to 15 extra minutes; tent the top with foil if it browns before the centre is set. Check the cake with a skewer near the new bake time. Open butter converter
How do I convert metric pan sizes to inches?: Divide centimetres by 2.54 to convert pan dimensions to inches. A 23 cm round is the same as a 9-inch round (the most common UK and EU size), and a 20 cm round is roughly an 8-inch round. Pan depth is usually labelled in centimetres too: 5 cm is about 2 inches, which matches the standard US cake pan depth. Open plain flour converter
Why does my batter spill over the edge of the pan?: The pan is too small for the recipe. Most cake recipes assume the batter fills the pan halfway to two-thirds, leaving room for the cake to rise. Pick a pan with at least 50% more volume than the original, or scale the recipe down with the batter multiplier and pour any leftover batter into a second pan of similar depth. Open sugar converter

More conversions

Convert ingredient measurements or fresh fruit and vegetables.

Updated 23 October 2026