Have you ever found the perfect cake recipe but it’s written for the wrong size pan? Maybe it’s a 6 inch cake recipe and you want to make an 8 inch cake, a batch of cupcakes, a sheet cake or even cute little mini cakes instead. That’s where cake recipe conversions come in. Once you know how to scale recipes up or down, you can bake any size cake you like without wasting ingredients or ending up with too much batter.
In this guide I’ll walk you through how to convert cake recipes for different pan sizes, how to adjust baking times, and how to work out exactly how much buttercream you’ll need, too.
Let’s start with an example. Imagine you’ve got a recipe for a 6 inch cake with three layers. That same recipe can be used to make other sizes of cake:
The secret to cake recipe conversions is understanding the volume of the different pans. You don’t need to do complicated equations yourself though – I’ve put together a simple chart that shows how many cupcakes are equivalent to different sizes of cake. Keep this handy and you’ll be able to adjust any recipe without any guesswork.
| Cupcakes | 4 inch cake(s) | 6 inch cake | 8 inch cake | Other | |
| 12 cupcakes | x 2 (3 layers) | x 1 (2 layers) | x 1 (2 layers) | 6x9 inch* | |
| 18 cupcakes | x 3 (3 layers) | x 1 (3 layers) | x 1 (2-3 layers) | 9x13 inch sheet cake | |
| 24 cupcakes | x 4 (3 layers) | x 1 (4 layers) | x 1 (3 layers) | 9x13 inch (2 layers) or 1 x 10" cake |
* You can use this batter to make a mini sheet cake or for a very thin 9x13 inch quarter sheet cake. Turn a thin sheet cake into a layered cake by cutting it in half and stacking, or cut out two identical numbers to make a number cake like this:
Once you’ve worked out which pan you’re using, you’ll need to tweak your baking time. This part is simple:
For deeper cakes, it’s also a good idea to lower your oven temperature to 10°C or 15°F less than the original recipe. This helps the cake bake evenly all the way through without the outside burning.
It’s always better to check early rather than risk an overbaked cake. For cupcakes, I start checking at around 16 minutes. For small or shallow cakes, I check from 20 minutes, and for wide or tall cakes I start checking from about 30 minutes. Press the top of the cake gently: if it springs back, it’s ready, but if your fingerprint stays, give it a few more minutes. The edges should also just start to pull away from the pan when it’s fully baked.
Running out of buttercream halfway through decorating is incredibly frustrating. Cake recipe conversions aren’t just about the cake batter – you’ll need to scale your buttercream too.
Here’s a simple guide based on my 4 Minute Buttercream, which makes about 6 cups of frosting (1.5kg). That’s enough to fill and frost an 8 inch cake with three layers. You'll see the ingredient measurements listed for each batch and below that, what you can frost with that buttercream.
| 6 cups of buttercream (1 batch) | approx. 3 1/2 cups of buttercream | approx. 1 3/4 cups of buttercream | ||
| Butter | 2 1/2 cups 5 sticks 568 g | 1 1/2 cups 3 sticks 339 g | 3/4 cup 1 1/2 sticks 170 g | |
| Powdered Sugar | 7 1/2 cups 2 lb 907 g | 4 1/2 cups 1 lb 3 oz 545 g | 2 1/4 cups 9 1/2 oz 272g | |
| Salt | 1/2 teaspoon | 1/4 teaspoon | 1/8 teaspoon | |
| Vanilla | 1/2 tablespoon | 1 teaspoon | 1/2 teaspoon | |
| Cream / Milk | 3 tablespoons | 2 tablespoons | 1 tablespoon | |
| Frosts which cake? | 8 inch (2-3 layers) or 9x13 inch (2 layers) | 6 inch (2-3 layers) or 9x13 inch (1 layer) | 4 inch (2-3 layers) | |
| Frosts how many cupcakes? | 24-36 cupcakes | approx. 18 cupcakes | approx. 9 cupcakes |
Cake recipe conversions open up so many possibilities! You can now make your favourite recipe in any size or shape of cake and with the right amount of buttercream, too. Whether you’re scaling up for a big party cake, scaling down for a smaller gathering, or turning a layered cake recipe into cupcakes, you’ll have the confidence to get it right every time.
I’d love to know what you’re converting next! Please share it in the comments below. And if you want to take your baking and decorating even further, visit my cake school for online courses and memberships where you can learn hundreds of cake decorating techniques and designs.
You can also watch a video of this tutorial on cake recipe conversions:
