What size cake for 20 people?
Twenty people, sixteen of them children. The size below is the smallest round tin that covers it on party slices, which is the number you want and not the one most charts show.
The answer
16 children aged 6 to 9 and 4 adults, 2:00 PM for 2 hours.
10inch round
A 10-inch round covers 24 party slices, enough for 18. Party slices are the larger cut. The wedding column of the same chart would claim far more from this tin.
SourcedWilton
The wedding number is not your number
This is the most common error on competing pages. The same tin is quoted two ways: a wedding slice is about one inch by two, a party slice about one and a half by two. Quoting the wedding figure makes an eight inch round look like it serves twenty four. It does not, and you will be cutting slivers in front of guests. Every cake figure here is the party slice.
This is a snack party, not a meal.
The rest of the list for this party
| Amount | Item | Part of the party | Basis |
|---|---|---|---|
| 16 | Snack portions | Food | Our rule |
| 5 | Prepared fruit | Food | Sourced |
| 20 | Cupcakes | Cake | Our rule |
| 42 | Juice boxes and soft drinks | Drinks | Sourced and our rule |
| 20 | Water bottles | Drinks | Our rule |
| 38 | Plates | Table | Our rule |
| 60 | Napkins | Table | Our rule |
| 18 | Goodie bags | Favors | Our rule |
Your party is not this party
Change the guest count, the ages, the start time or the weather and the whole list moves. The calculator opens on the party above, so you can adjust it rather than start again.
Where these numbers come from
- Planning the quantity food occasion, University of Minnesota Extension. Checked 2026-09-27.
- Ultimate cake serving chart, Wilton. Checked 2026-09-27.
- Beverage math: how much to serve at your event, Plum Deluxe. Checked 2026-09-27.
- Accurate food and beverage quantity guide for your guests, Occasional Occasions Catering. Checked 2026-09-27.
Anything marked our rule is our own judgement rather than a published figure. We say which is which so you know which numbers to argue with.
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