What Size Birthday or Wedding Cake Do I Need?
- Marie-Clare Anderson
- Apr 17, 2025
- 9 min read
Updated: Jan 30
Are you confused as to what size cake you need for your birthday or wedding celebration? You’re not alone! This is one of the most common questions I get asked, and honestly the internet can make it even more confusing! There are so many different answers floating around, even as a cake maker, I find it overwhelming at times.
A children’s birthday party with excited children running around who just want a bite of cake will have very different portion requirements to, for example, an elegant wedding reception where guests just want a small bite with coffee, or to an adult birthday party where appetites are perhaps alittle bigger! I know I always go back for seconds!
That’s why I’ve created this simple, no-fuss guide to help you understand cake sizes so you can order the perfect cake for your celebration, of course, you are also welcome to just ask me for my advice.
Firstly, let's chat about the different size portions you can serve
My cakes are all 4 layers tall, so one slice is a pretty generous serving. Here is a quick breakdown of the four standard cake portion sizes to help you decide what sort of slice you think you'll need for the big event.
1. The Dessert Slice (For Cake Lovers!)
📏 Size: 2 inches x 1 inch deep (full height of cake, approx. 5.5 inches)
🍰 Perfect for:
Serving as dessert after a meal (this could be paired with cream or fresh fruit)
Adult birthday parties where guests want a generous slice.
Smaller gatherings where cake is the main event.
This is a generous portion, especially if the cake is rich (think chocolate ganache and caramel!). It’s best served on a plate.
2. The Wedding Cake ‘Finger’ Slice (Elegant & Classic)
📏 Size: 1 inch x 1 inch deep (full height of cake)
🍰 Perfect for:
Weddings & formal events where cake is served after dinner as an extra sweet
Lighter portions that go well with tea or coffee.
This is the standard wedding cake portion—just enough to enjoy without feeling too full.
3. The ‘Walk & Talk’ Slice (Easy to Hold!)
📏 Size: 2 inches x 1 inch deep (half the cake’s height)
🍰 Perfect for:
Casual parties & evening receptions where guests are mingling.
Events where people will be standing, holding drinks & chatting.
Believe it or not, this is the same amount of cake as the wedding slice above, but easier to hold and eat while socialising.
4. The Bite-Sized Slice (For Just a Little Sweetness)
📏 Size: Tiny squares or rectangles (smallest portion option).
🍰 Perfect for:
Weddings & large events where guests might already be full.
Dessert tables where people are grazing.
When you want to serve cake canapé-style (passed around on trays).
A great choice if you love the idea of cake but know your guests won’t eat much. I think this is the best size if you want a wedding cake as an extra to pudding (or dessert). You can have a smaller wedding cake, so save a few pounds, but you still get the excitement of designing your very own wedding cake and cutting it on the day.
So, What’s the Best Size for You?
Still not sure? Here’s a quick guide based on the type of celebration you are having.
Birthday Party Cake Size Guide
I've included some scenario's here to give you a better idea what cake size you may want that would suit your occasion. Obviously, there are no hard rules, if you and your friends all love cake then you'll know you will want a cake that provides generous portions, but if you are unsure I hope this helps.
Adult Birthday Party
If you are having a large adult birthday party where guests are mingling, perhaps you are offering a buffet, or finger food, drinks and dancing, people are usually standing chatting rather than sitting down to eat. For this type of celebration I think Option 2 - The Walk And Talk Slice works best. It offers your guests get a decent slice of cake that's easy to hold, and enjoy whilst socialising.
On the other hand, if you would like to celebrate your birthday with cake but you are offering plenty of other food or dessert options then, Option 3 - Bite-Size is perfect. Everyone still gets a taste of cake, and it reduces the risk of too many leftovers.
Small intimate Party
If you are celebrating with a small group of close friends or family, perhaps over lunch or dinner in a restaurant, or at home, then enjoy your cake as dessert. For these occasions, I would recommend Option 1 - The Dessert Slice. A generous slice of cake that everyone can enjoy.
Children’s Birthday Party
For younger children, I would generally recommend smaller slices. Young children are often too excited to eat much cake, and I have found that quite a bit of cake gets leftover on plates. For this reason I would recommend Option 2- The Walk And Talk Slice, easy to hold and it still looks a reasonable portion.
Older children and teenage parties are a different matter. They tend to have much bigger appetites so I would strongly recommend Option 1 - The Dessert Slice to allow for generous portions.
Looking for the perfect birthday cake for your party? You are luck! Check out my Birthday Gallery here for inspiration.
Birthday Cake Guide
Cake Width | Dessert Slice (1”x2”x full height of cake) | Walk & Talk Slice (1”x2”x half height of cake) | Bite-size (1”x1”x half height of cake) |
4 inch | 6 servings | 12 servings | 24 servings |
5 inch | 8 | 16 | 32 |
6 inch | 12 | 24 | 48 |
7 inch | 16 | 32 | 64 |
8 inch | 24 | 48 | 96 |
9 inch | 32 | 64 | 128 |
10 inch | 38 | 76 | 152 |
My advice | Best as dessert or for an adults party | Good standard size especially for children, easy to handle | Best for canapes or after a large meal |
Wedding Cake Size Guide
Traditionally, wedding cake slices are fairly small. This is because the wedding cake is usually served after the wedding breakfast, so the cake is in addition to all the other food your guests have already enjoyed.
If the cake is not being served as dessert, then I would usually recommend you cater for approximately 75% of your guests. After a large meal, not everyone will want cake and unless the cut cake is placed in the best location for people to see it and therefore eat, there is often quite abit leftover.
Below are a few common scenario's and serving ideas to help you decide what size cake will work best for your wedding.
The Wedding Finger Slice
The wedding finger slice is the classic traditional choice. This is a thin elegant slice that looks beautiful on a plate and works well for formal, seated settings.
However, it's not ideal for guests who are standing up or moving around. If your guests will be mingling or dancing when cake is served, this wouldn't be my first recommendation.
The Walk & Talk Slice
Personally, I love the walk & talk slice. To me, it looks more satisfying while still being easy to eat without cutlery.
However, if your guests are likely to be full from the wedding breakfast or the three-course meal they’ve just enjoyed, or if you’re also offering evening food, then the Bite-Sized Slice is a great alternative. It’s a perfect little sweet treat without feeling excessive and helps minimise waste.
Serving cake as dessert
In the end, it’s all about what works best for your celebration.
For my own wedding, we served the cake as dessert so it actually got eaten and so we could enjoy it ourselves! We followed it up cheese, but that's a whole other menu decision!
Cake boxes to take home
Another lovely option is to provide cake slices in boxes for guests to take home.
A friend of mine choose the Walk & Talk Slice for this. It looked generous in the box, was easy to wrap up, didn't fall apart and was still easy to eat.
Ready to chat all things wedding cake? From flavour and style to colours and theme, take a look at my wedding cakes here.
Wedding Cake Guide
Cake Width | Dessert Slice (1”x2”x full height of cake) | Wedding Finger (1”x1” x full height of cake) | Walk & Talk Slice (1”x2”x half height of cake) | Bite-size (1”x1”x half height of cake) |
4 inch | 6 servings | 12 servings | 12 servings | 24 servings |
5 inch | 8 | 16 | 16 | 32 |
6 inch | 12 | 24 | 24 | 48 |
7 inch | 16 | 32 | 32 | 64 |
8 inch | 24 | 48 | 48 | 96 |
9 inch | 32 | 64 | 64 | 128 |
10 inch | 38 | 76 | 76 | 152 |
My advice | Best as dessert. | Elegant, best served on a plate | Good standard wedding size and easy to handle | Best for canapes or after a large meal |
Wedding Cupcakes as an alternative
Wedding cupcakes are another popular option. There is no cutting required, the cakes stay moist in their cases, and guests can easily help themselves and eat on the go.
If you are considering cupcakes, I would recommend you cater for 95-100% of your guests. People are much more likely to take one, and often will go in for a second helping, especially if there is more than one flavour on offer!
Cupcakes are also a great way to accommodate dietary requirements, with less risk of cross-contamination compared to a tiered cake.
Excited to see all the flavour options you could have at your wedding? Take a look at my cupcake flavour menu here.
So having got this far, you should feel abit more confident is choosing a size of cake that suits your day best. Remember there’s no right or wrong choice, at the end of the day no-one ever complained about having to eat leftover cake!
And if you still aren't sure, I am always happy to chat to you about sizing, and will often provide you with two sizing options to give you the choice of a smaller or larger cake.
What is the best way to cut your cake?
One of the best tips I can give you for getting the most slices out of your cake is to cut it in a grid pattern. Yes, traditionally we cut cakes in pie-style wedges but cutting in a grid makes slicing easier and is more efficient, especially for larger cakes.
Here's a quick guide to get the most out of your cake.
Follow this guide to get the maximum portions from your cake based on 1" x 2" servings x half cake height (the Walk & Talk Slice)
If you want larger slices (Dessert Slices) then just slice vertically, this will give you half the amount of suggested servings and a generous slice of cake! This is show in brackets above.
Need More Help? Let’s Chat! 💬
I hope this guide makes ordering your perfect cake so much easier! But if you’re still unsure about sizes, don’t worry—I’m happy to help.
📩 Send me an email, and I’ll recommend the perfect cake size for your celebration.
🎂 Let’s make sure everyone gets a slice of something delicious!
Have a few more questions about cake sizes? Check out my Frequently Asked Questions below.
How Many Servings Will Each Cake Size Provide?
The number of servings depends on how you cut the cake. Here’s a simple guide:
If you’re serving cake as dessert, you’ll need a slightly larger cake than if it’s just for small portions after a meal.
❓ Do You Offer Multi-Tier Cakes?
Yes! If you need a cake for a bigger event, a two- or three-tier cake is a great way to serve more guests while keeping the design beautiful. Let me know how many people you need to serve, and I’ll recommend the perfect tier sizes.
❓ How Tall Are Your Cakes?
All of my cakes are four layers high. Depending on the filling, this gives a finished height of around 5 to 6 inches—so you’re getting a lovely, tall slice every time!
This also allows for alternate fillings if you fancy going for that extra indulgent flavour choice. 😋
❓ Can I Mix Portion Sizes for One Event?
Absolutely! Many clients mix and match portion sizes to suit different parts of their event. For example, some couples choose Wedding Finger Slices for the formal cake-cutting and larger Dessert Slices for the evening reception.
❓ What If I Want Leftovers?
If you want extra cake for the next day (or just because cake is amazing!), consider: ✔ Sizing up by 1 inch. ✔ Choosing a tiered cake for extra servings.
❓ Can I Freeze Leftover Cake?
Yes! Most cakes freeze beautifully.
Just:
✔ Wrap slices tightly in cling film or in between baking parchment
✔ Place in an airtight container.
✔ When ready to eat, defrost at room temperature for a few hours.
✔ Best to eat within a month of freezing - though I doubt they will be eaten long before then!
Perfect for keeping a slice of birthday or wedding cake as a treat later!
❓ Do You Provide Cake Stands or Cutting Guides?
✔ If you need a cake stand for display, I have options available for hire.
✔ I also provide a cutting guide so you can get the most servings from your cake.
❓ What If I’m Still Unsure?
No worries at all! If you’re still unsure what size to choose, just drop me a message, and I’ll help you decide on the perfect cake for your celebration.
📩 Get in Touch for Cake Advice
Ready to Order Your Cake? Let’s Create Something Delicious!
If you now have a better idea of the cake size you need, let’s chat! Whether it's for a birthday, wedding, or special celebration, I’d love to create something perfect for you.
📩 Order Your Custom Cake Here Today
📷 Follow me on Instagram for more cake inspiration: @cakesbymarieclare
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