Published 7 May 2026 · By Paulina · 6 min read

What Size Cake Do I Need?
The Complete Portion Guide

Never order the wrong size cake again. This guide tells you exactly how many people each cake size serves, so you can order with confidence.

Ordering a cake that is too small is a disaster. Ordering one that is too big wastes money. Getting the size right is one of the most important decisions when ordering a celebration cake, and it is simpler than you might think. This guide gives you exact portion counts for every cake size, so you know exactly what to order.

Round Cake Portion Guide

Round cakes are the most popular shape for birthdays, weddings and celebrations. Here is how many people each size serves:

Cake SizeParty PortionsDessert Portions
6 inch round10 to 128 to 10
7 inch round15 to 1812 to 14
8 inch round20 to 2415 to 18
9 inch round25 to 3020 to 22
10 inch round30 to 3824 to 28
12 inch round45 to 5535 to 40
14 inch round65 to 7550 to 55

What Is the Difference Between Party and Dessert Portions?

Party portions are slim slices, roughly 1 inch wide and 2 inches deep. This is the standard serving at events where cake is one of many food options, like a buffet, afternoon tea or a party with lots of other treats.

Dessert portions are generous slices, roughly 2 inches wide and 2 inches deep. This is what you would serve when cake is the main dessert, such as after a sit down dinner or at a small gathering where the cake is the centrepiece.

For most birthday parties and celebrations, party portions are the standard. For weddings where cake is served as dessert after dinner, use the dessert portion column.

Multi Tier Cake Portion Guide

When you stack two or more tiers, the portions add up. Here are the most popular tier combinations:

Tier CombinationTotal Party Portions
8 inch + 6 inch (two tier)30 to 36
10 inch + 8 inch (two tier)50 to 62
10 inch + 8 inch + 6 inch (three tier)60 to 74
12 inch + 10 inch + 8 inch (three tier)95 to 117
14 inch + 12 inch + 10 inch + 8 inch (four tier)160 to 186

Cake Size by Guest Count

Here is a quick reference if you know your guest count and just need to know what to order:

Tips for Getting the Size Right

  1. Count actual cake eaters, not total guests. Not everyone eats cake. At a wedding, roughly 70 to 80 percent of guests will have a slice. At a children's party, almost everyone will
  2. Consider other desserts. If you are also serving a dessert table, cupcakes or other sweets, you can go one size smaller on the main cake
  3. Children eat half portions. If half your guests are children, you can reduce your portion count by about 25 percent
  4. Better slightly too big than too small. Running out of cake is far worse than having a few slices left over. Leftover cake keeps beautifully in the fridge for 3 to 5 days
  5. Ask your baker. If you are unsure, message Paulina with your guest count and she will recommend the perfect size

The Sheet Cake Trick for Large Events

Hosting a large event but want a beautiful cake without the cost of a massive tiered design? The sheet cake trick is your best friend. Order a stunning one or two tier display cake for photos and the cake cutting moment. Then have a plain sheet cake in the kitchen, pre sliced and ready to serve to guests. Nobody will know it came from a different cake, and you will save a significant amount of money.

This is especially popular at weddings and large corporate events where guest counts exceed 100.

Not Sure What Size to Order?

Tell Paulina your guest count and she will recommend the perfect cake size for your celebration.

Ask Paulina
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