Hello! Today I’m going to answer the most frequently asked question by my clients and students. Which cake size should I bake / order for my event?
The short answer: It depends! The most important factors that come into play, are the number of guests in attendance, but also what kind of food will be served, and how much!
Now for the long answer:
If your cake is going the be the main dessert, plan at least one serving for each guest. But if you are planning on serving a seven-course wedding feast, or having a buffet of several desserts, then it will be enough to order half the amount of servings, so each guests can get a half-serving.
Of course, this leads to the next question:
How big is a cake serving?
This decision is usually up to the baker. This is why all the serving charts you find on the internet are different – because each bakery has decided on a custom serving size. Fondant cakes of today are usually filled with several layers of buttercream or ganache. This makes them quite rich to eat, compared to traditional European pastry cakes like Black Forest cake, that is very airy and filled with whipped cream. A wedding cake portion does not have to be huge, nor does a children’s birthday cake because both groups of people usually are too full to eat big slices of cake. Also, do take into account that fondant cakes tend to be quite high, 10cm (4 inches) and more!
Here at Minh Cakes, our standard serving size is 5 cm x 10 cm x 2.5 cm
(2 inches x 4 inches x 1 inch).
For a wedding dessert, it’s a generous amount of cake. I’ve heard that in the UK, it is customary to serve only half this amount – the wedding cake is meant as a little teaser and not as full-fledged dessert.
Method 1: Determine cake size using volume calculations
The way to determine the amount of servings per cake, is by using volume calculations (yes that’s geometry folks!) My standard serving is 125 cm³ (8³ inches). Using cylindrical volume formulas, it’s easy to calculate the amount of servings per tier.
A round cake is basically a cylinder. That’s why we can use this formula:
Volume = radius square * π (Pi) * height
Example
Take a 20 cm (8″) diameter cake that ist 10cm (4″) high. The radius is 10 cm (4″).
In cm: Volume of the cake: 10 cm² * π * 10 cm = 3141 cm³
In inches: Volume of the cake: 4² inches * π * 4 inches = 201³ inches
Now we just have to divide the volume of the cake, with the volume of the serving, and we’ll get the number of servings:
In cm: Servings: 3141 cm³ / 125 cm³ = 25 servings
In inches: Serving: 201³ inches / 8³ inches = 25 servings
Result: A 20 cm (8″) cake that is 10 cm (4″) high, will yield 25 servings that are 2.5 x 5cm (1″ x 2″) large.
This is the exact mathematical method. For each tier size I sell, I could calculate the geometrically correct number of servings:
However… (yes, there’s always a BUT)… I don’t actually work with the numbers above. Why? There are three reasons:
- Due to my preferred method of cutting (more on that later), some cake slices end up having more fondant & ganache and have to be calculated bigger then 125 cm3.
- Other slices of cake are pierced with dowels.
- And lastly, we do want to make sure we are generous with our brides.
That’s why we declare a slightly lower number of servings per tier in our sales. How is this calculated? I really recommend the next method…
Method 2: Determine cake size using apps
Since we aren’t all math geniuses, we need all the help we can get! And help comes in the form of some very useful smartphone apps. There are some very clever ones on the market (and by the way, they all use the basic formula above in their calculations!). My favourite app is called Tiered Caker.
It lets you easily configure the serving size and tier sizes that you have in your own kitchen. Then you send yourself the cutting guides by email!
These are the 5 tier sizes that we sell, and the corresponding cutting guide. As you can see, the amount of servings per tier is slightly lower than in the chart above. Note that the slices in the corners are a bit larger to account for fondant + ganache cover!
You can find our actual chart in our Cake FAQ (in German for now).
Now you know how to calculate the amount of servings for each tier size. As soon as you have these numbers, you can start to play around and combine them until you get the number of servings you need for your next event.
A few examples:
 |
 |
 |
| 10cm + 15cm (4+6″): 19 servings |
10cm + 15cm + 20cm (4+6+8″): 41 servings |
15cm + 20cm + 25cm (6+8+10″) 73 servings |
I think I know what you next question is: How do I cut a cake following these cutting guides?
The answer is coming in the next blog post! 🙂
I hope this information has served you. I’d love to know if you have another way of calculating your servings – please leave comments & questions below!
Love and happy calculating,
