One of the most common questions we receive is "what size ice cream cake do I need?" It seems simple, but getting the size right matters more than you might think. Order too small and you'll have disappointed guests; order too large and you're left with a mountain of leftover cake that may not store well. This guide provides practical formulas and considerations to help you choose the perfect size ice cream cake for any occasion.
Understanding Ice Cream Cake Measurements
Ice cream cakes are typically sized in one of three ways, and understanding these measurements helps you compare options:
By Weight
Most supermarket ice cream cakes list their weight in grams or kilograms. A typical range is 750g to 1.5kg for standard cakes. Generally:
- 750g - 900g: Serves 6-8 people
- 1kg - 1.2kg: Serves 8-12 people
- 1.3kg - 1.5kg: Serves 12-16 people
- 1.5kg+: Serves 16+ people
By Diameter (Round Cakes)
Premium and specialty ice cream cakes often specify diameter:
- 15cm (6 inches): Serves 4-6 people
- 20cm (8 inches): Serves 8-12 people
- 25cm (10 inches): Serves 12-16 people
- 30cm (12 inches): Serves 16-24 people
By Stated Servings
Many manufacturers indicate "serves X-Y" on packaging. Treat these as guidelines—manufacturer serving sizes tend to be on the smaller side. If generous portions are your style, subtract 20-30% from the stated maximum servings.
📏 Measurement Reality Check
Manufacturer serving counts assume precise, restaurant-style portions. Real-world home serving tends to be more generous. When in doubt, assume you'll get fewer servings than stated.
The Guest Calculation Formula
Here's a practical approach to calculating how much cake you need:
Step 1: Count Your Guests
Start with your confirmed guest count. For parties with RSVPs, add a small buffer (about 10%) for unexpected attendees.
Step 2: Adjust for Guest Types
Not all guests eat the same amount. Consider these adjustments:
- Children under 5: Count as half portions
- Children 5-12: Count as three-quarter portions
- Teenagers: Count as full portions (or more—they can eat!)
- Adults who won't eat dessert: Don't count these guests
- Ice cream cake enthusiasts: May want seconds; count as 1.5 portions
Step 3: Consider the Event Context
- Dessert-only event: Plan for larger portions
- After a full meal: Smaller portions are usually sufficient
- Buffet with multiple desserts: Reduce portions by 30-50%
- Hot weather: People may want more refreshing ice cream cake
🔑 Key Takeaway
For most events, plan on 80-100g of ice cream cake per adult guest as a standard portion. Adjust up for dessert-focused events, down for events with multiple sweet options.
Size Guide by Event Type
Different celebrations have different expectations. Here's guidance for common scenarios:
Children's Birthday Parties
- Small party (5-8 children): 750g-1kg cake
- Medium party (8-15 children): 1kg-1.3kg cake
- Large party (15-25 children): 1.5kg+ cake or two smaller cakes
Remember that children's portions are smaller, but children's parties often mean cake goes home with guests. Factor in parent portions if adults will be served too. See our complete guide to ice cream cakes for children's parties for more details.
Adult Birthday Parties
- Intimate gathering (4-8 adults): 1kg cake
- Standard party (10-15 adults): 1.2-1.5kg cake
- Large celebration (20+ adults): Two 1.2kg cakes or one premium large format
Family Celebrations (Christmas, Easter, etc.)
- Nuclear family (4-6 people): 900g-1kg cake
- Extended family (10-15 people): 1.3-1.5kg cake
- Large family gathering (20+ people): Multiple cakes or a large format option
Note: Holiday meals typically feature multiple desserts, so ice cream cake portions can be smaller.
Office and Workplace Events
- Small team (5-10 people): 1kg cake
- Department (15-25 people): 1.5kg cake
- Large office event (30+ people): Multiple cakes or sheet cake format
Consider that not everyone will eat cake at work events. A general rule is to plan for 60-70% participation.
✨ Pro Tip
For large events, consider ordering two different flavours rather than one huge cake. This offers variety and makes serving easier—you can have two cutting stations operating simultaneously.
The "Too Much vs. Too Little" Dilemma
When uncertain, should you order more or less? Here are considerations for each approach:
Arguments for Ordering Larger
- Leftovers can be enjoyed for several days if stored properly
- Running out of cake is more embarrassing than having too much
- You can send guests home with portions
- Larger cakes often offer better value per serving
Arguments for Ordering Smaller
- Ice cream cake doesn't store as well as traditional cake
- Freezer space may be limited
- Less food waste is environmentally responsible
- Cost savings
The Middle Ground
A practical approach is to order for your expected guest count plus 10-15%. This provides a small buffer without significant excess. If you're truly uncertain about attendance, consider having a backup plan—a container of quality ice cream that can supplement if the cake runs short.
Special Considerations
Dietary Restrictions
If some guests have dietary restrictions (dairy-free, vegan, nut allergies), you may need to account for a separate smaller cake. Factor this into your overall sizing. See our guide to vegan and dairy-free options for more information.
Tiered or Multiple-Cake Displays
For weddings or formal events requiring an impressive display, calculate your total serving needs first, then distribute across multiple cakes. Note that tiered ice cream cakes require more complex logistics due to weight and melting concerns.
Leftovers Strategy
If you anticipate leftovers, plan for storage:
- Ensure adequate freezer space before the event
- Have containers or wrap ready for portioning leftovers
- Consume leftovers within 5-7 days for best quality
For detailed storage advice, see our guide on how to store ice cream cake.
🎯 Quick Sizing Guide
- 6-8 guests: 750g - 1kg
- 10-12 guests: 1kg - 1.2kg
- 12-16 guests: 1.3kg - 1.5kg
- 20+ guests: 1.5kg+ or multiple cakes
- Add 10-15% buffer for uncertainty
- Reduce by 30% if offering multiple desserts
When Standard Sizes Don't Work
Sometimes you need a non-standard size. Options include:
- Custom orders: Many bakeries and specialty stores offer custom-sized ice cream cakes
- Multiple smaller cakes: Instead of one 2kg cake, get two 1kg cakes for easier handling and variety
- Individual portions: Ice cream cake cups or bars eliminate sizing concerns entirely
- Supplement with extras: A smaller cake plus individual ice cream treats gives flexibility
Ready to find the perfect ice cream cake for your event? Browse our product comparison and filter by serving size to find options that match your needs.