One of the most popular questions I get asked is “How to convert cake recipes for different size pans with the same height?”.
Maybe you have a recipe that tells you to use a 6-inch pan, but all you have at home is an 8-inch pan or what do you do when you don’t have the right cake pan?

When converting cake recipes, first thing that you need to know is “How much the surface area of each of the pans?” (the pan you want to use and the pan the original recipe calls for).

There is a little maths involved in working this out, but to make it a little easier I have done this for you by using the simple chart below:

Once you have your 2 surface areas you can work out your Adjustment Amount

Then you can use the adjustment amount to convert the original recipe; by multiplying the value of the adjustment amount by the amount of each original ingredient

EXAMPLE OF ADJUSTING RECIPE

Here’s an example of how I converted one of my cake recipes;
My Vanilla Cake Recipe was for a 6-Inch Round cake and I wanted to use my 8-Inch Round Pan

The surface area of 6-Inch Round Pan (according to chart) is 29; and 8-Inch Round Pan is 50
To get the Adjustment Amount, I will divide 50 by 29 = 1,72

After multiplying all ingredients by 1,72 (as shown by the math above), I was able to bake the cake in my 8″ cake pans which produced the same height, texture and consistency as my 6″ cake pans.

WHAT ABOUT EGGS, BAKING POWDER/ Soda, SALT AND EXTRACT?!

For eggs – work off of a standard egg weighing 50g (out of the shell).
If you only need 25 grams of an egg, crack an egg into a cup whisk and measure out 25g using scales (save the leftovers for other purposes).

For ingredients like Baking Powder/ Soda or Lemon Juice
I round up or down e.g. if 1 tsp Lemon Juice is needed for 6″ , I round 1,72 up to 1, 75 (which is 1 ¾ tsp)

Another helpful trick is to follow the rule; the standard ratio is 1 teaspoon Baking Powder per cup of Flour and 1/4 teaspoon Baking Soda per cup of Flour.

Salt and vanilla are little more easier to play around with seeing as they are flavour enhancers only and don’t affect the structure of the cake. 

DO I NEED TO ADJUST THE BAKING TIME?

Please note that changing pan sizes may change your baking time, so DON’T forget to adjust the baking time.
It is hard to tell how much you will need to adjust the time by as this will depend on the size difference; generally, a bigger pan has more liquid and needs more time baking.

For a SMALLER pan start checking 5-10 minutes prior to the stated time, and for a LARGER pan add time in 5-minute increments until it is baked
(Below is an example of how I increased and decreased the baking time)

DO I HAVE TO DO THE MATH?

If this all seems like too much hard work, I get it!
If you are using a smaller cake pan than what the recipe states, you could just make the recipe as usual and follow the general rule of thumb which is to fill the cake tin 2/3’s full.
Any left over cake mixture can be used for mini cupcakes to be frozen and used for another time.

In the opposite scenario (the cake pan you have is larger than the required in the recipe), then you could multiply the recipe by 1.5 or 2 depending on how much larger the cake tin is; But in fairness, if you’re going to do some math anyway you may as well do it precisely and get it right with the method above.

I hope this was helpful for you.
Happy baking! 🥰