Cake Serving Calculator

Calculate how many servings you can get from your cake based on shape, size and portion type.

6"
15cm
8"
20cm
10"
25cm
12"
30cm
14"
35cm
16"
40cm

Find the perfect cake size for your guest count.

UK Cake Portion Sizes Explained

Professional UK bakers use standardised portion sizes to ensure consistent serving counts. The right portion size depends on the occasion and whether cake is the main dessert or part of a larger spread.

Wedding Portion

1" × 2" × 4"

Finger slice style. Ideal when serving other desserts.

Party Portion

1.5" × 2" × 4"

Standard birthday party slice. Good all-rounder.

Dessert Portion

2" × 2" × 4"

Generous slice when cake is the star dessert.

Round Cake Serving Guide

Cake Size Metric Wedding Portions Party Portions Dessert Portions
6 inch 15cm 12 8 6
8 inch 20cm 24 14 10
10 inch 25cm 38 20 14
12 inch 30cm 56 30 21
14 inch 35cm 78 40 28
16 inch 40cm 100 50 35

Square Cake Serving Guide

Square cakes yield approximately 25-30% more servings than round cakes of the same dimension due to their larger surface area.

Cake Size Metric Wedding Portions Party Portions
6 inch 15cm 18 12
8 inch 20cm 32 20
10 inch 25cm 50 30
12 inch 30cm 72 45
14 inch 35cm 98 60
16 inch 40cm 128 80

Tiered Wedding Cake Guide

Traditional UK wedding cakes typically feature multiple tiers with 2-inch size differences between each tier. The classic combination starts with the largest tier at the bottom for stability.

Popular Tiered Cake Combinations

Configuration Tier Sizes Wedding Servings Party Servings Best For
2-tier 6" + 8" 36 22 Small intimate weddings
2-tier 8" + 10" 62 34 40-60 guests
3-tier 6" + 8" + 10" 74 42 60-75 guests
3-tier 8" + 10" + 12" 118 64 100-120 guests
4-tier 6" + 8" + 10" + 12" 130 72 120-130 guests
4-tier 8" + 10" + 12" + 14" 196 104 180-200 guests

Pro Tip: The Top Tier

The top tier of a wedding cake is traditionally kept for the couple's first anniversary or christening. If you plan to save it, order an extra 6" cake for cutting and don't include the top tier in your serving count.

Professional Cake Cutting Tips

How to Cut a Round Cake

Method 1: Circle Cut

  1. Cut a circle 2" from the outer edge
  2. Cut the outer ring into 1" or 1.5" slices
  3. Repeat with inner circle
  4. Cut centre into wedges

Best for: Maximising portions from large cakes

Method 2: Grid Cut

  1. Cut parallel lines across the cake
  2. Turn 90° and cut perpendicular lines
  3. Creates rectangular portions
  4. Some edge pieces will be curved

Best for: Speed and uniformity

Tools You'll Need

  • Long serrated knife: For cutting through multiple layers
  • Cake server: For lifting and placing slices
  • Warm water: Dip knife between cuts for clean slices
  • Ruler or guide: For consistent portion sizes
  • Kitchen towel: To wipe blade between cuts

Fondant Cakes

For fondant-covered cakes, use a thin, sharp knife rather than serrated. Score through the fondant first, then cut. Wipe the blade after every cut to prevent dragging.

UK Wedding Cake Costs and Budgeting Tips

Planning your cake budget is just as important as getting the portion count right. UK wedding cake prices vary considerably depending on the baker, design complexity, and your location.

Average UK Wedding Cake Prices (2025/26)

A professionally made three-tier wedding cake in the UK typically costs between £350 and £800, though elaborate designs with sugar flowers, hand-painted details, or metallic finishes can exceed £1,500. High-street supermarket wedding cakes from Marks and Spencer, Waitrose, or Costco range from £80 to £250 for three tiers and offer excellent value. Home bakers and small independent businesses often charge between £200 and £500 for a three-tier design. London and the South East tend to be 20 to 30 percent more expensive than other regions.

Cost-Saving Strategies

One popular approach is to order a smaller decorative display cake for photographs and the cutting ceremony, supplemented by matching sheet cakes kept in the kitchen for serving. A beautifully decorated two-tier display cake might cost £200 to £400, while a plain sheet cake providing 50 to 80 additional portions costs just £30 to £60 from a supermarket. This approach can save 40 to 60 percent compared to having all portions come from the tiered display cake. Another option is a semi-naked or buttercream finish, which is typically cheaper than fondant and has become a popular aesthetic choice in its own right.

Ordering Timeline for UK Bakers

Popular wedding cake bakers in the UK often book up 6 to 12 months in advance, particularly for summer wedding season between May and September. Place your order at least 4 to 6 months before your wedding date. Schedule a tasting session 6 to 9 months ahead, as most reputable bakers offer this service either free of charge or for a small fee (typically £20 to £50) that is deducted from your final order. Confirm all details including delivery logistics, set-up arrangements, and any venue restrictions at least one month before the event.

Frequently Asked Questions

A 10-inch round wedding cake typically yields 38 wedding-sized portions (1" × 2" finger slices) or 20 party-sized portions (1.5" × 2" regular slices). For dessert portions (2" × 2"), expect approximately 14 generous servings. These counts assume a standard 4-inch tall cake.

For 100 guests with wedding portions, you'll need approximately a 3-tier cake (8", 10", 12") which provides 118 wedding servings. Alternatively, a single 16" round cake serves 100 wedding portions. Always order 10-15% extra for seconds and unexpected guests.

Square cakes provide approximately 25-30% more servings than round cakes of the same dimension due to their larger surface area. A 10" square cake yields about 50 wedding portions versus 38 from a 10" round. Square cakes are also easier to cut into uniform portions.

Buttercream cakes can be pre-cut up to 2 hours before serving if covered. Fondant cakes should ideally be cut just before serving as the exposed sponge can dry out. For large events, professional caterers may pre-portion into containers. Fruit cakes can be cut days in advance.

For children's parties, use party-sized portions as children typically eat more cake than at weddings. For 20 children, an 8" round cake (14 party portions) plus cupcakes works well. Alternatively, a 10" round cake provides 20 party portions with some extra for adults.

Yes! Order 10-15% extra servings beyond your guest count. This covers: guests who want seconds, late RSVPs, serving staff samples, take-home portions for those who can't attend, and any cutting mishaps. Consider a hidden "cutting cake" in the kitchen to supplement if needed.

Common conversions: 6" = 15cm, 8" = 20cm, 10" = 25cm, 12" = 30cm, 14" = 35cm, 16" = 40cm. UK recipes and tin sizes often use both measurements. When in doubt, measure the actual inner diameter of your tin at the widest point.

For maximum servings per pound of cake, sheet cakes are most efficient with minimal waste. Square cakes come second, followed by round cakes. However, tiered round cakes offer the classic wedding aesthetic. Consider a combination: decorative tiered cake for display and sheet cakes in the kitchen for serving.

UC

Reviewed by: UK Calculator, Founder & Developer

Founder & Developer - UKCalculator.com

The UK Calculator team is the founder and developer of UKCalculator.com, providing free, accurate calculators for UK residents.