Wedding cake sizes - your complete guide
Updated: Feb 18
I quite enjoyed maths at school. I was never brilliant at it, but I liked how precise it was, and that there was always a right or wrong answer. When I became a professional wedding cake designer, I was surprised by how much of my job would involve a high level of mathematical precision, and it’s yet another reason I get a kick out of what I do.
Every time I discuss wedding cake sizes with my clients, we need to do a bit of maths. Here’s the equation:
How many people you want to serve x how big you want your servings to be = wedding cake size
It’s pretty simple really, which is why it drives me a bit mad how unhelpful most of the internet is when you try and get answer to how big a cake you will need. A quick google throws up lots of cake sizing charts which appear very helpful on first glance. But on closer inspection you have probably realised that they can vary wildly in terms of what they advise, with little to no explanation for why.
So I am on a one baker mission to set the record straight on cake sizing and here is my definitive guide:
How many people do you want your wedding cake to serve?
This should be the easy part right? You’re having 100 guests, so you need a cake to serve 100?
Well, yes and no. As a rule, I don't tend to advise that my couples cater for their entire guest list. We all have those friends who are watching their waistline, or perhaps you know a few of those peculiar types who ‘don’t really like cake’ (???!!!) For this reason, it is unusual for every guest to take a slice. At the same time, you may also have some real cake fiends amongst your number who will want to try all the flavours or go back for seconds. For this reason I generally suggest catering for around 80% of your overall guest number. This usually allows everyone who wants cake to have some, and those keen beans to have a bit extra too.
The obvious exception to this is if you are serving the wedding cake as dessert, in which case you will want to cater for everyone. The other exception is if you want to have some cake leftover to enjoy with friends and family in the days after the wedding. If this is the case, let your wedding cake maker know and they can factor this in.
What size cake servings are you going to offer?
This is the really important part, and is the main reason that advice varies so much on the correct wedding cake size for your number. Depending on how it is cut a cake can serve very different numbers of people, and both bakers and clients alike will have different preferences on serving size. My solution? Look at all the options and go from there.
A note on tier height - Just one more bit of explanation before I delve into this. There is one more variable that needs to be considered when figuring out a cake’s size and that is your tier height. Another reason that a lot of the charts you find online are not enormously helpful is that they are a bit out of date. Going back 15-20 years or so, a standard wedding cake tier was usually about 3” tall. However, modern wedding cake tiers are usually around 5-6” tall. That’s a big difference in terms of slice size. Some cake designers have even taller tiers as standard. To complicate matters even further, you may be opting for a cake with tiers of varying heights. If this is the case, your cake maker will advise on the specific sizes you need and what will work for your guest number. To keep things as simple as possible, I am offering the advice below based on a cake tier height of 6”, which is my personal standard.
Oh and last thing I promise – When you have cut a cake in the past, it’s probably been in wedges. However, for ease of serving (and because I think they look nicer), I always recommend that your cake is cut in rectangular pieces. This is the industry standard and your venue/caterers will know to cut the cake this way, but I always provide a guide anyway.
Option 1: The dessert slice
2” wide by 1” deep and the full height of the cake (so here that is 6”).
I generally recommend this serving size if you are serving your wedding cake as dessert, maybe alongside some fruit and cream.
Note, if you are serving your cake in the evening, after a lot of food and dancing, this is probably too big a slice for most people and might put them off taking some. For this reason I don’t tend to suggest this unless my couples know they have a guest list that is overflowing with cake lovers who will be absolutely furious if they don’t get a big slice of cake.
Because of its size, this slice should probably be plated, but if not you will definitely need napkins for serving.
Option 2: The wedding cake ‘finger’ slice
1” wide by 1” deep and the full height of the cake.
This is what you may have heard referred to as a ‘finger’ slice and is one of the most classic ways to serve a wedding cake. It looks lovely and elegant and provides a nice amount of cake for people who are full from dinner but have worked up a bit of an appetite dancing.
The only problem with these slices is because they are long and thin, they can be a little tricky to lift one handed. This can make it a bit tricky for people to help themselves, especially if they have a drink in the other hand! For this reason I actually suggest going for option 3 if you want this size of slice.
Option 3: The ‘drink in the other hand’ slice
2” wide by 1” deep and half the full height of the cake.
With these slices, you are getting the same amount of cake as option 2, but because of the shape they are much easier to lift, hold and eat. You don’t even need a napkin with these, making them ideal for guests who have a drink in the other hand.
Option 4: The bitesize slice
1” wide by 1” deep and half the height of the cake
OK, I’ll admit it, these are pretty tiny. However, if you have a lot of evening food laid on, a full dessert table, or a group of guests who you just know won’t want a lot of cake, this may be the option for you. This gives people a little taste of something sweet without the commitment of a big slice.
This serving size works nicely if your caterers are able to take the cake round on trays and serve 'canapé style'.
And now here’s my (excellent and accurate) chart :)
This should help to give you a sense of the kind of wedding cake size you will need. Note that tiered cakes go up in 2" increments (e.g. 4",6" and 8"). Of course, you don't need to work this out yourself. If you enquire about a wedding cake with me I will do all the maths and give you the different options that will work for your guest number. But if you want to have an idea then this is the chart to use.
As a final guide, I've taken some different examples of wedding cake sizes to show how varied your serving number could be depending on how the cake is cut:
So there you have it! A full and definitive guide to wedding cake sizes. I really hope this was helpful. If you are looking for a wedding cake in London or Surrey and you like to chat more with me more, please get in touch here.