Birthday cake slices
See the size of each slice and what is in it, for planning a party.
Your details
Sponge with butter icing, cut into 12
357 kcal a slice
75 g slices with 30.0 g of sugars
- Daily free sugars guide, age 7 to 1024 g a day
- One slice is125% of that
- A smaller slice (half)179 kcal
- Slices for little onescutting the cake into more slices suits younger children
Birthday cake is part of the celebration, and nobody needs to burn it off. For children, smaller slices and water with the cake make it easier on teeth. Figures are CoFID 2021.
Your health visitor, school nurse or GP can help if you are worried about a child's eating.
The working
A 900 g sponge with butter icing, cut into 12
Each 75 g slice has 357 kcal and 30 g of sugars (CoFID 476 kcal and 40 g per 100 g). For children aged 7 to 10 the free sugars guide is 24 g a day, so a half slice suits little ones well.
Cakes compared
Per 100 g, CoFID 2021
| Cake | kcal | Sugars |
|---|---|---|
| Sponge with butter icing | 476 | 40 g |
| Chocolate cake with butter icing | 452 | 36 g |
| Iced fruit cake | 355 | 59 g |
| Shop sponge with jam and buttercream | 354 | 38 g |
Party ideas
For a happy, easy party
- Cut more, smaller slices for younger children
- Serve water and milk with the cake
- Cupcakes make portions easy
- Games and dancing make the party, not the food
Read with care
What this cannot tell you
- Weigh your cakeHome bakes vary.
- Set rules for treatsBirthday cake is part of celebrating.
- Count party foodAdd other treats separately.
Questions
Common questions
How many calories in a slice of birthday cake?
Around 300 to 400 kcal for a 75 g slice of iced sponge.
How many slices from a cake?
A 20 cm round cake gives about 12 to 16 party slices.
How much sugar should children have?
No more than 19 g of free sugars a day at 4 to 6, 24 g at 7 to 10 and 30 g from 11.
Is birthday cake bad for children's teeth?
Eating it in one go at the party, with water, is far kinder to teeth than sweets all day.
Sources
- McCance and Widdowson's Composition of Foods Integrated Dataset 2021 (CoFID)
- NHS: sugar in our diet (adults no more than 30 g of free sugars a day; 19 g for ages 4 to 6, 24 g for 7 to 10)
- NHS: taking care of children's teeth
Last checked 21 October 2026. Spotted something wrong? Tell us and we will fix it.
Help for children
Your health visitor, school nurse or GP can help with worries about a child's eating, teeth or activity. Call NHS 111 for urgent advice.
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