### CakeWhat to CookBakingKitchen Hacks

# How to Make Your Baking Recipe Fit Your Pan Size

*Every week, baking expert Alice Medrich will be going rogue on Food52—with shortcuts, hacks, and game-changing recipes.*

*Today: Alice Medrich's famous brownies are made in an 8-inch pan, but you'll want to make a sheet pan-worth. Here's how you can make that happen with just a little math.*

The brownie recipe you want to make calls for an 8-inch square pan, but your only square pan is a 9-inch. Should you risk it? Maybe you want to double or triple a recipe but you aren’t sure which pan to use, or maybe you have a specific large pan but don’t know how many times to multiply your recipe in order to fill it.

**The answers to these and similar questions (asked endlessly in cooking classes!) do not involve rocket science, but just enough elementary school math to calculate the area of a square, rectangle, or circle.** I love the math (and I’ve included a little math review below if you want to brush up), but I’m sharing my chart in case you don’t have my thing for math.

The handy list below (or some basic math, also explained below) will tell you the surface area of your pan. Once you know the area of any pan, you can compare it to the area of another pan to see how much bigger or smaller it is. **You can divide the area of a large pan by the area of a small pan to figure out how many times to multiply a recipe to fill the larger pan with the same depth of batter **(more on that later).

**Handy list** (with the numbers rounded up to the nearest inch):

Area of square/rectangle pans:

- 6 x 6 = 36 square inches
- 7 x 7 = 49 square inches
- 8 x 8 = 64 square inches
- 9 x 9 = 81 square inches
- 9 x 13 = 117 square inches
- 12 x 16 (half-sheet pan) = 192 square inches

Area of round pans:

- 5 inch = 20 square inches
- 6 inch = 29 square inches
- 7 inch = 39 square inches
- 8 inch = 50 square inches
- 9 inch = 64 square inches
- 10 inch = 79 square inches
- 12 inch = 113 square inches

I don’t always have the chart at hand; I often just do the math!

For squares and rectangles: The area of a square or rectangular pan is calculated by multiplying one side times the other side. The area of an 8-inch square is 64 square inches because 8 x 8 = 64; the area of a 9 x 13-inch pan is 117 square inches because 9 x 13 = 117. Easy.

For rounds: The area of a circle equals π times the radius squared. In case you don’t remember, π = 3.14; the radius of a circle is half of its diameter; and squaring means multiplying a number by itself. Ready? To calculate the area of an 8-inch round pan, multiply 3.14 (π) by 4 (because it’s half of 8) times 4. Thus, the area of an 8-inch circle is 3.14 x 4 x 4, approximately 50 square inches. Not so hard!

Just by glancing at the two pans, you might think that a 9-inch pan is very close in size to an 8-inch pan of the same shape, thus making it a reasonable substitute. But if you check the chart, you’ll find that a 9-inch square pan is more than 25% larger than an 8-inch square pan. (The relationship between a 9-inch and 8-inch round pan is similar.) Such a considerable difference will result in a 9-inch batch of very thin brownies that may be over-baked by the time you check them for doneness (because thin brownies bake faster than thick ones). Knowing this beforehand, you can increase the recipe by 25% for results as thick than the original recipe intended. If you want brownies that are even a tad thicker than the original recipe, you can even increase the recipe by 33%.

Let's try an example: How many times should you multiply an 8-inch brownie recipe to fill a 9- x 13-inch pan or a 12- x 16-inch half sheet?** To figure this out, divide the area of the larger pan by the area of the 8-inch pan. **

- For the 9- x 13-inch pan: 117 divided by 64 = 1.82, which is close enough to 2 that you can confidently double the recipe for the larger pan.
- For the half sheet: 192 divided by 64 is exactly 3, so you can multiply the recipe times 3.

Using similar math, you can calculate how many times to multiply the recipe for a round cake to make a large rectangular sheet cake. And don’t forget that you don’t always have to multiply recipes by whole numbers—it’s perfectly fine to multiply a recipe by 1 1/2 or 2 2/3.

About now, you might be wondering about eggs. It’s nice if you can increase recipes so that you don’t have to deal with fractions of eggs—by increasing a 2-egg batter by 1 1/2 or a 3-egg batter by 1/3 or 2/3, for example—but it is not essential.

**Here’s what to do if you multiply a recipe and end up needing part of an egg:** Set aside any whole eggs you need. Next, whisk the other egg to blend the white and yolk; weigh it (preferably in grams); then weigh out the fraction of the egg that you need for the recipe and add that to the whole eggs. If you need 40% of a 50-gram egg, that’s 20 grams of the whisked egg. When egg whites and yolks are used separately, weigh and measure them in the same way, but separately. Add leftover egg parts to your morning scramble. See, no waste and still no rocket science!

The chart (or your ability to do the math) is extremely valuable: Use it but don’t be a slave to it. When I make brownies in a large quantity, I like them to be about the same thickness as they are in a small batch, so I stay close to the chart. But, when I increase the dimensions of a birthday cake, I often make it a bit taller than the original (in other words, I round up when multiplying) because the proportions are visually more pleasing. For example, if I am making a 12-inch round cake using a recipe meant for an 8-inch pan, I divide the area of the 12-inch round pan (113) by the area of the 8-inch round (50 inches) and get 2.26. But instead of multiplying the recipe by just 2.26, I might multiply it by 3 so that the cake will turn out tall and lofty. See: Love the chart, but don’t let it bully you!

**When you round things up like that, don’t go overboard: Pans should not be filled more than about 2/3 full or batter may overflow.** If you do end up with too much batter, scrape the excess into cupcake molds or a mini cake pan—bonus cakes never go uneaten!

**When you increase recipes and bake in larger pans, you should anticipate longer baking**—anywhere from a little longer if the pans are filled to the same level as the original recipe to considerably longer if you are making the cake taller by filling the pan a bit more. If you are making a smaller amount of the recipe, check earlier than you think you need. And always use a cake tester to check to see if the cake is finished.

*Pick up a copy of Alice's new book Flavor Flours, which includes *nearly 125 recipes * -- from Double Oatmeal Cookies to Buckwheat Gingerbread -- *made with wheat flour alternatives like rice flour, oat flour, corn flour, sorghum flour, and teff

*(n*ot only because they're gluten-free, but for an extra dimension of flavor, too).

## Comments (108)

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out ofcomments## 29 days ago Grazi

I'm curious, if I'm converting a cake recipe normally intended for 8-inch round pans to mini pans, should i also lower the temperature, as the overall density of the batter is also less? I've always winged this and just lowered the temp by about 25 degrees F and watched it for doneness.

## about 2 months ago Karen Jacobs

Hi, can I ask with increasing from an 8" to a 12" round cake (making a victoria sponge cake in a 12" loose bottomed tin so I will need to use my cake cutter do divide it into 2 before putting jam/buttercream in) With 2.26 should I double the recipe, times by 2.5 or triple it?

Yours a math-o-phobe with a headache! x

## about 2 months ago Don Brabston

As I understand your question, you want to go from an 8" circular pan to a 12" circular pan. In that case, you'll need to increase the batter by a factor of 2.25/ (You could make it a factor of 2.5 to be safe, but 2.25 is the correct factor.) So, if for example, the recipe calls for 4 cups of flour, you'll need to use 9 cups instead. Let us know how it turns out, and if you have any jam/buttercream left over, send it my way ...

## 2 months ago Samantha Vimes

Or you could check on your thin brownies sooner.

## 3 months ago Luisa Carvalho

Hello I have a recipe for a 6" cake pan, but I need to make 2 cakes, one in 10" and another in 12" cake pans, do I need to make 3,5 and 4 times the recipe for this two pans??

Thank you so much for your help.....

## 3 months ago Ciara

You are heaven sent! Thanks so much :)

Question: if I wanted to concert a 6" round recipe into a 10" square recipe, that would mean roughly I would be using 3.5 times the ingredients (100/29=3.44), is that correct?

## 3 months ago Don Brabston

Yup. For the same depth of batter, you're only concerned about the ratio of the areas to determine how much to multiply the batter by. The area of a 10" square pan is 100 square inches, and the area of a 6" (diameter) is pi times the radius (3") squared or about 28.3 square inches. 100 divided by 28.3 is about 3.5, so just multiply the amount of batter used for the 6" round by 3.5 in order to fill the 10" square pan to the same depth.

## 3 months ago Jerry Couch

When I was in school, I did not understand diameters (rounds) nobody took the time to explain how to arrive at an answer, I almost always made things harder than they were. Thanks for the math lesson.

## 4 months ago Greg

Great article. Thank you! When increasing amounts, how do you adjust the ratios for chemical leaveners like baking powder. If I quadruple the flour, should I also quadruple the baking powder?

## 4 months ago Rahul Bhanushali

Thanks for the recipe.

Gonna try it today.

www.govt-job.guru

## 4 months ago Lina

I would like to bake a six inch cake. I'm using the 56% you provided for another post listed below. I want to make sure I'm doing this correctly. I will multiply all the ingredients by 56% and that will be the amount I use.

Thanks for your help in advance!

## 4 months ago Don Brabston

Yup. That should be correct. With 56% of the ingredients, you should have the same depth batter in the 6" round tin as for the full recipe in an 8" round tin.

## 4 months ago Colleen

I would like to make a carrot cake that calls for a 10-inch tube pan, but want to convert into a sheet pan. With the same volume would I be better using a 10 x 15 pan or 12 x 17 pan?

## 4 months ago Don Brabston

The worst possible answer: it depends. Assuming that, by a 10" tube pan, you mean a Bundt pan that is 10" in diameter, you still need to know the diameter of the interior "pole". I don't have a Bundt pan, so I can't make a measurement. From pictures of Bundt pans, they look like a 10" Bundt pan has a central pole with a diameter of maybe 2.5". If that is the case for the 10" pan you're talking about, the area of the annulus to be filled with batter is about 74 square inches. (This does not account for any taper of the central pole from bottom to top.) A 10 x 15 pan has an area of 150 square inches, or roughly double the area of the Bundt pan, so you'll need to double the amount of batter you make for the Bundt pan to fill the 10x15 sheet pan to the same depth. (The 12x17 pan will need even more batter, so I'd just stay with the 10x15 pan.) Another factor to consider is that the baking time for the Bundt pan will be less than a sheet pan filled to the same depth since the Bundt pan cooks from the inside out as well as the outside in. So, I'd probably double the amount of batter called for by the Bundt pan recipe, use the 10x15 sheet pan, and start checking for doneness when the Bundt pan recipe says its cake should be done. Let us know how it turns out.

## 5 months ago Anita

Hi Alice, thank you for this in depth explanation. Can you tell us what the equation is if you want to go from a larger pan to a smaller one. My recipe is for a 8in round tin but need to make it in a 6in round. What do we do in this situation?

## 5 months ago Don Brabston

To determine the amount of batter for a given depth in a round tin, just remember the area of a circle formula: A = pi * r2 (r2 = r squared = r * r). And then the volume of a cylinder V = A*h, where A is the area of a circular cross-section of the cylinder, and h is the height of the cylinder. Since you're dividing the volume of one cylinder b y the volume of another cylinder of the same height (batter depth), the height, h, and the constant pi cancel out of the ratio, and you're left with the square of the ratio of the circle radii (or, equivalently, diameters). So, as an example, to go from an 8" tin to a 6" tin, just square the ratio 6/8, and get 0.5625. Therefore, you'll need about 56% as much batter for the 6" tin as for the 8" tin.

## 5 months ago Gwen Samson

I am making my daughters wedding cake and I have nightmares because it did not work for my sons 6 years ago. On the theory please check if I am correct with the sizing. A 7 inch tin is 38.46 and a 10 inch tin is 78.5. Difference is 40.04. Do I up the recipe by another 1.4% of ingredients. Maths has never been my strong point. Many thanks

## 5 months ago Don Brabston

No, no ... the ratio of 78.5 to 38.48 is about 2, so you need to double the ingredients to get a cake batter of the same depth, in going from a round tin of 7" diameter to one of 10".

## 5 months ago j123

hey i have these mini cake silicon molds and I don't know or can't find a recipe for a pan that is 2 inches wide and 3 inches long I know it is really small but I want to make a small cake. Is it possible or does anyone know a recipe for that small cake? I would really appreciate it to get some help :-)

## 5 months ago Cecília Muriscot Geli

Hi! I found a great cheesecake recipe but the "problem" is that the recipe calls for two 8in round pans. I would like to make just a bigger one. I was thinking of using a 10in springform pan. I've checked each pans volume and in total, two 8in pans equal one 10in. The time that the recipe suggests is 250ºF in a water bath for 1 hour and 40 minutes. Should I change it? Or can I keep both temperature and time? Thanks a lot

## 5 months ago Don Brabston

I'm not sure, but mathematically, 2 8" pans would seem to me about 28% bigger in area than one 10" pan, so ...

If the volume of the 2 8" pans is the same as one 10" pan, the 10" pan must be deeper, hence the batter would be thicker than the 2 8" pans combined and much thicker than one 8" pan. So ...

If the time of 1h40m is for an individual 8" pan, I would plan on increasing the time by about 50% (to 2h30m) and start checking at around 2 hours, but maybe I misunderstand your question entirely.

## 5 months ago Cecília Muriscot Geli

Thank you very much! I'll see how it goes!:D

## 5 months ago lin

I need to convert a recipe for a 6inch pan baked at 350 degrees for 25 minutes to an 8 inch pan. I will increase the recipe by .75. How long do I bake it.

## 5 months ago Don Brabston

If by "increasing the recipe by .75", you mean that you'll make .75 more of the recipe (e.g., go from 4 cups to 7 cups), then you should have about the same depth of batter in the 8" pan and the baking time should be about the same (I.e., bake at 350 for 25 minutes).

## 6 months ago Shannon

Ok, so my maths is awful and I am in South Africa, so the inches is making it worse for me to work it out. Please help me. I have to make a 40cm x 40cm cake for a customer for next Friday. My usual recipe makes a double layer 25cm round cake. Please tell me how many times I need to multiply my recipe by to make the 40cm x 40 cm cake. 🙃🌸

## 6 months ago Don Brabston

You don't say whether your 40 cm square cake is to be a double layer cake or not. Assuming that it is also to be a double layer cake like the original 25 cm round cake, you'll need to increase the recipe by a factor of approximately 3.25. (The area of the 40 cm square pan is 1600 square cm, and the area of the 25 cm (diameter) round pan is about 490 square cm, so the ratio is about 3.25.)

## 6 months ago mcs3000

Thank you for doing the math for us - so helpful. SAVING this!

## 6 months ago Linda

Convert egg white muffin recipe to baking pan?

## 6 months ago Peggy budd

I wish to use Allison Fryers recipe for an 8" spring form "Chocolate Cloud Cake" but I only have a 9" spring form. Will this work or do I have to increase the ingredients by 15% ? (this is a flourless, 6 eggs & chocolate)

## 6 months ago Don Brabston

It seems to me that if you want the same depth in the pan, you need to increase the ingredients by about 25% (26.525% to be exact). (That is (9/8)^2. I would guess that with the same depth in the pan, the cooking time and temperature should be about the same as your current recipe.

## 6 months ago Peggy budd

Thanks Don, would it be better to go down a size to a 7" pan? what are your thoughts. thanks!

## 6 months ago Don Brabston

Peggy,

I'm not sure from a cooking standpoint. I'm sure there others in this forum who are better able to answer that. I can say that if you go to a 7" pan, you'll need about 25% less of the ingredients as compared to the 8" pan (and, of course, you'll get about 75% as much cake).

## 6 months ago Peggy budd

Don, thanks for your thoughts.

## 7 months ago kate

If you are looking to convert and scale your recipes I would suggest you look at 'Baking It' http://www.bakingit.com.

This piece of software enable any baking business owner to to add in their recipes and convert and scale them to suit your needs. This is just one of the awesome features of this software. I can literally do everything I need to here to run my baking business. create orders, email customers, list ingredients, even design cakes for slicing guides.

Worth checking out.

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