Kitchen Hacks

How to Make Any Baking Recipe Fit Any Cake Pan Size

June 27, 2019

Award-winning cookbook author Alice Medrich is here to help you bake smarter, not harder, with game-changing recipes and aha-moment techniques. Today, we're breaking down a question we've asked ourselves, oh, a million times: How do we adapt cake pan sizes in baking recipes? (Say, something calls for a 8x8-inch, but you only have an 9x9.) Alice will show you 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.

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How do you adapt different cake pan sizes for different recipes? 

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

Geometry review:

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.

Here are five baking recipes to put your newfound knowledge to good use: 

1. Triple-Chocolate Olive Oil Brownies

Bittersweet chocolate, chocolate syrup, and Dutch-process cocoa powder make these brownies as chocolatey as can be. We love the olive oil's grassy flavor, but feel free to swap in canola if you're not a fan. 

2. Cook's Illustrated's Blondies

Meet the blondie recipe that will ruin you for all others. Don't say we didn't warn you! Made with melted butter, they're just as gooey and fudgy as a blondie should be. 

3. Peanut Butter Sheet Cake 

"Bake this peanut butter sheet cake for birthday parties, celebrations, or just because," writes recipe developer EmilyC. "It's so easy to assemble, feeds a crowd, and will put a smile on everyone's face." 

4. Magic Cookie Bars

When we say magic, we mean it. These classic cookie bars include graham cracker crumbs, sweetened condensed milk, semisweet chocolate chips, toasted nuts, shredded coconut, and coconut flakes. Oh, and butter, because of course. 

5. Lemon Bars With a Salty Olive Oil Crust

While most lemon bar crusts are butter-based, like a classic shortbread, this one opts for a modern upgrade: olive oil instead. A generous pinch of salt brings out the olive oil's savoriness in a way the lemons really love. Serve extra-cold with confectioners' sugar dusted on top. 

This article was originally published in June 2015. We refreshed it for this summer, because we're very, very excited about our summer dessert to-do list. What are your tricks for adapting recipes to different pan sizes? Tell us in the comments!

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  • Shu
  • foxy
  • Jmnewman2
  • Anna Go
    Anna Go
  • ebraxy
My career was sparked by a single bite of a chocolate truffle, made by my Paris landlady in 1972. I returned home to open this country’s first chocolate bakery and dessert shop, Cocolat, and I am often “blamed” for introducing chocolate truffles to America. Today I am the James Beard Foundation and IACP award-winning author of ten cookbooks, teach a chocolate dessert class on, and work with some of the world’s best chocolate companies. In 2018, I won the IACP Award for Best Food-Focused Column (this one!).


Shu October 23, 2020
Most recipes seem to be for 8", 9" or the 9x13 pans. So, I did the conversions for the pans I own.
Note the conversions are rounded off to the nearest multiple of 5.

So if I want to scale a 9x9 square pan recipe to my 8x8 square pan, I'll just use 80% of the 9x9 recipe.
Eg: 100g of flour will be 80g of flour.
Calculator entry: '100' x '0.8' = 80.

Hope this helps someone out there.

Area of square/rectangle pans:
* 7 x 7 = 49 square inches = Same as 8” round
* (75% of 8” square)
* (60% of 9” square)
* (40% of 9 x 13)
* f**k it. Just half either 9” sq or 9 x 13 recipe
* 8 x 8 = 64 square inches = Same as 9” round
* (80% of 9” square)
* (50% of 9 x 13)
* 9 x 9 = 81 square inches
* (125% of 8” square)
* (70% of 9 x 13)
* 9 x 13 = 117 square inches
* (180% of 8” square)
* f**k it. Just double a 8” sq
* (140% of 9” square)
* f**k it. Just x1.5 a 9” sq

Area of round pans:
* 4 inch = 13 square inches
* (20% of 9” round)
* (25% of 8” round)
* 6 inch = 29 square inches
* (45% of 9” round)
* (60% of 8” round)
* f**k it. Just half either 8” or 9” round
* 8 inch = 50 square inches = Same as 7” square
* (75% of 9” round)
* 9 inch = 64 square inches = Same as 8” square
* (125% of 8” round)
foxy September 22, 2020
Hello, I am new to baking and the only pans I have are 6*3. So I was just wondering if I could use the a 6*3 as a 6*2 pan?
Don B. September 22, 2020
I assume you mean To convert a recipe for a pan that is 6” long by 3” wide (6x3) to one that is 6” long by 2” wide (6x2). If that's what you mean, then, yes it's possible to do that. There are two ways I can think of. One way is to just make the same amount of batter as for the 6x3. Then, either use 2/3 of the batter; the resulting cake will be the same depth and should cook about the same. Or you could use all of the batter, but the cake will be 50% deeper and take longer to cook. The other way would be just to make 2/3 of the recipe and use all of the resulting batter; then the cake will be the same depth and cook the same as the original recipe. Hope this helps.
Jmnewman2 June 21, 2020
I am trying to Convert a brownie recipe that is for an 8x8 pan up to a 13x18 pan and it works out to be 3.65 times bigger so would I just times the original recipe by 4 or would I have to go 3.65 times bigger? I can easily multiply all the ingredients by 3.65 except the eggs since im pretty sure it will be next to impossible to use 7.3 eggs and 3.65 yolks🤣. Thanks!!
Don B. June 21, 2020
the easy way would be to multiply the entire recipe by 4 and then just use 90% of it (giving a factor of 3.6). but my guess is that you could use the entire 4X of the batter, which would make just make the batter a little (about 9%) deeper and the brownies that much thicker. then just bake it a little longer. (start checking at your usual time.)
Anna G. May 12, 2020
Thank you for this helpful guideline! I pretty much understand how to adjust a recipe now (I think) but what about for let’s say, a recipe I’m following uses a 3 layer 6” round cake pan, and I’ll be using a 2 layer 8” round cake pan. (Both have the same 2” depth)
So first, Following your chart, i’ll divide 50 by 29 = 1.7 as the multiplier. (270g flour x 1.7 = 459g)
But that would amount to a 3 layered 8” pan... what about the 1 extra cake layer that i don’t want, how exactly do i subtract that?
Sorry for All my basic math skills have basically flown out the window...
Anna G. May 12, 2020
I’m not sure if anyone would follow but if my previous calculation was correct, i now have 459g of flour for a 3 layer 8” round cake pan.
If i want to make just 2 layers instead of 3, I’ll divide 459g by 3 = 153g approx. for 1 pan. 153 x 2 = 306g of flour for 2 layers/pans
Can anyone tell me if this is correct?
ebraxy May 2, 2020
Thank you for writing this out, but it seems like you left off in the middle. I'm sorry I don't remember my basic math. I want to scale down from 8" round to 6" round. Using what you have shown I end up with a difference of 1.79. Where do I go from there to take 480g of flour to a 6" round. Thanks
Smaug May 2, 2020
Actually, you want the reciprocal of that; 6sq./8sq.=.56, .56x480=270g.
Don B. May 2, 2020
yes, the difference in volume (assuming equal depth of batter) is the ratio of 1.78 (8^s / 6^2). so simply divide the 480g of flour used for the 8" round by 1.78. you get approximately 271g of flour for the 6" round. now, dividing eggs by 1.78 is a little trickier :)
mompants April 11, 2020
This is brilliant, thank you so much for this! I never would have guessed that a 9” round is so much smaller (in capacity) than a 9x9” square.
Thank you for saving my Easter bunz!
mudd February 10, 2020
Easy way to consider this issue-surface area only. But need to also consider capacity/volume. Eg recipe calls for 8x8x2 in high. You have 8x8x1 in high. Surface are of both is exactly the same-64 in-but capacity/volume is very different. Volume of 8x8x1 is 64 sq in, 8x8x2 is 128 sq in!
Smaug February 10, 2020
Not really very relevant. If you're making soup or jello you can size your container by volume (to some extent) but in a baking recipe changing the depth significantly will have a huge effect both on the baking characteristics and the finished quality of the dish- it's generally to be avoided when adapting recipes.
mudd February 10, 2020
That’s just what I’m trying to point out. Volume of pan can make a huge difference in baking!
Smaug February 10, 2020
Then I'm not sure of the point of your post. If you're adapting a recipe, the depth of your pan should be similar to that of the original recipe, there's no real point in factoring in volume. It can be deeper, to some extent, but a too deep pan can slow down heat absorption from the top which may or may not be acceptable, and can also make it difficult to remove some things without damage; best to stay away from it. If you want to halve a recipe for a 1" deep pan you need a 1" deep pan, or close to it, with about half the surface area.
mudd February 11, 2020
I’m trying to respond to some of the previous commenters/questioners below is all.
Katherine F. January 26, 2020
I'm very new to baking, so this may be a no-brainer question, but i did the math and the difference between a 9 and 9.5 in tart pan is 1.1. Do i really need to increase the ingredients by .1%? I know you have to be pretty darn exact with baking..
Smaug January 26, 2020
Actually, the difference is 11.4%- you can usually get away with ignoring it, but your filling may come out a bit thin. The need for exactitude in baking is greatly overstated- there are some things, such as fat to flour or liquid to flour ratios- where small changes can make a big difference (not necessarily a bad thing), but a lot of it is pretty wide open to variation.
Don B. January 26, 2020
The ratio of the area of the two pans is the square of (9.5/9), or 1.114. This means the difference is .114 (1.114-1) or 11.4%, so you need to increase your ingredients by about 11%, not 0.1%.
Linda December 26, 2019
Would you post a chart like you showed for baking pans, for cheesecake pans?
Recipe calls for one size and maybe you don’t have the same size or you want to create your own cheesecake but not sure how much of each ingredient you’d need.
Bala R. December 19, 2019
Such an interesting post!!! Loved the Math u have explained.. U have made it easier now..I have one small doubt.. For a round pan, the radius is alone taken into account for the calculation.. What if the pan's height varies?!! Assuming my pan is taller, the amount of batter gets in will be more than a shorter pan right?!! So how do you incorporate the pan's height?!!!

Waiting for your response. Thanks in Advance 😊
Smaug December 19, 2019
When adapting a recipe, particularly cakes and pies, the baking characteristics are largely dictated by the depth as that determines the time needed for heat to penetrate to the center as well as the weight (particularly for cakes) that the structure should support. Therefore, every effort should be made to maintain the depth of the original recipe. Thus, for 1/2 the recipe you need 1/2 the surface area. Of course this seldom works out exactly with the pans you have but if it's not close the recipe will need considerable adaptation and may fail. Cooking a shallow cake in a deep pan will interfere somewhat with heat circulation to the top and is to be avoided if possible, but it's seldom disastrous and is often the only real alternative.
Rosalind P. January 2, 2020
yeah -- it's very frustrating. I have more pans that any sane home baker should have, especially for a New York-sized kitchen, yet I'm always running across recipes for a size I don't have. The most frustrating is for the different depths: 2 inch or even three inch.
mudd February 10, 2020
See my above response. Multiply area by height!
Bala R. February 10, 2020
Thank you for the response.. Baking is more of the Math.. isn't?!!
Smaug February 10, 2020
Well, there's a certain amount of simple arithmetic involved in multiplying or dividing recipes, and if you're developing recipes you will be working with some basic ratios, such as fat to flour or liquid to powdered ingredients. Things with a lot of chemistry behind them, such as ice cream, will have more such ratios, but if you've mastered long division youshould have no problem with the arithmetic. Of course it's all "word problems"- you have to understand the processes to know what calculations to make.
Diana S. September 26, 2019
I have found that, if you are starting your cake with a boxed mix, a full-sized sheet cake pan of approximately 18x26 will easily handle four boxed mixes.....just don’t add a lot of extras. I do this for poke cakes, Texas sheet cakes, blueberry coffee cake. Works great!
Bala R. February 10, 2020
I hear u!!! Same here!!!
Bala R. February 10, 2020
Am sorry.. wrongly replied to your message...
AnneB September 15, 2019
This "simple" math made my head hurt. I didn't make it half way before I started feeling so stupid that I gave up. Too hard. :-(
Sharon I. September 10, 2019
Thanks, Don! I know I can figure this out -- you and Alice give me all the confidence I need!
Janet M. August 4, 2019
Problems like these conversions make me so happy I learned basic arithmetic in grade school--these are exactly like word problems I struggled through--and mastered--in 6th grade back in the mid-1950s. My problem before this article was that I was mostly thinking in terms of volume instead of surface area.
Cheryl S. June 28, 2019
Had a great time nerding out with this piece. Quants rule!!
Smaug June 27, 2019
A lot of times, you don't actually need to calculate areas, if you're comparing pans of the same shape. For instance, if you want to compare the area of a 9" round pan and an 8" round pan, it's a simple proportion of 9squared/8squared, or 81/64- 1 1/4 is close enough for baking. Since to calculate the area you're multiplying the diameter by pi/4 in both the numerator and denominator, they cancel each other out.
GBChelle May 25, 2019
Hi! I found Ina Garten’s recipe for brownies that makes a sheetpan (12x18). But I love my brownies thick. Do you think it would work to make them in a 9x13 pan and just bake them longer? Or will that just be too much batter and the weight of all of that better would cause them to sink in the middle and not cook properly?
Sara May 3, 2019
This post is extremely helpful. Especially the chart. However, I’m having some uncertainty with scaling down, which seems to be what I need to do based on the volumes. I’m trying to determine how to scale the recipe/ingredients of three 8” rounds to one 9x13. Please help!
Thank you!
Don B. May 4, 2019
simple question, but it can be a little tricky. your original recipe for three 8" rounds has a surface area of about 151 square inches, whereas your 9"x13" pan has a surface area of 117 square inches. therefore, to fill your rectangular pan to the same depth as the three round pans, you'll need about 22% less batter (that's (151-117)/151 = .22 ). so, for example, if your recipe calls for 5 cups of flour, you'll actually need about 3.9 cups of flour.
Sara May 4, 2019
Oh boy, that’s a bit tricky. Thank you very much for the reply.
Sara May 4, 2019
I actually just thought of a clever solution! Make the recipe as is, weigh the finished batter, and remove about 1/4 (or as close to 22% I can get) of it, and use that for a few cupcakes. You’re reply was very helpful. Now I truly understand how to scale a recipe down with your example and calculations. Thank you again!
Don B. May 4, 2019
great idea. let me know when I can come over for a cupcake :)
Rosalind P. February 10, 2020
or make the recipe as is and use the leftover batter for cupcakes
Rosalind P. February 10, 2020
oops. too hasty. cupcake suggestion already made. sorry
Lorie P. April 30, 2019
So I did the conversion also using another method and using this method and another method my answer comes to roughly 1.8, my question is, is this the same factor you use if using multiple Cake layers? Recipe I’m using calls for 6, 6 inch rounds however I’m using 6, 8 inch rounds?
Don B. April 30, 2019
Yup. going from a 6" round to an 8" round of the same depth means you need to multiply your recipe by 1.8, which is (8/6)^2 .
Lolly April 17, 2019

I just found the most perfect cake recipe which may sound strange to most people but I am allergic to eggs, milk and have celiacs disease so cannot have wheat either. I haven’t had cake for a lot of years now well not without being ill :-/ The recipe I found is the first one to not have odd stuff in like a lot have chickpea flour which does not appeal to me and other various odd things.... whole other story... Anyhoo the recipe calls for a 9 inch round cake tin and says cook for 30-35 mins. I only have 8 inch cake tins which I do love and I have had a go at using which it looked absolutely perfect consistency when I was putting into the tins before it went into the oven.... I checked at 35 mins (not thinking of the relevance of the size) and it looked pretty good but wasn’t done (so gave another 5 and checked then another 5) looked really good and squewer came out clean... obviously out of practice at making cakes and forgot the whole opening the door who ha so collapse situation.. tastes good though! Do you think the time was right in total so next time if I did for 45 without opening the oven it would be ok or any theories on maths with the time for the smaller tin. Please let me know. May just have to suck it up and go buy 2x 9inch ones! Many thanks x