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CrumbCalc

What Size Cake for 15 Guests?

Cutting party slices, a single 8" round seats about 20 — enough for 15. Every option is below.

15 guests need

8" round

about 20 party servings (1½ × 2 in slice) · see all options below

Data & method: Serving counts from the published Wilton cake serving chart (4-inch-tall cakes; party 1½ × 2 in slice, wedding 1 × 2 in slice). Every figure is checked by an automated test. How we calculate →

Check any size or head count

Preset to 15 guests — the reverse lookup below the tiers finds the smallest fit.

Serving style
+ Add tiers for a tiered or wedding cake

Serves about

20

party slices (1½ × 2 in)

Your cake, tier by tier

Next: how much frosting for this cake? →

Or plan backwards — how many guests?

We'll find the smallest cake that seats them, using the party/wedding slice size selected above.

An 8" round seats about 20 party servings — enough for 15.

Every way to seat 15

The chart below shows the smallest cake that covers 15 guests for each shape and slice size — all from the same Wilton figures the calculator uses. "Party" slices are 1½ × 2 in slice; "wedding" slices are the slimmer 1 × 2 in slice, which is why the wedding options run smaller.

Option Smallest fit Seats about
Round, party slices 8" round 20
Square, party slices 8" square 20
Round, wedding slices 8" round 24
Sheet, party slices 7×11" sheet 24

A single cake covers this comfortably. If you'd rather make a moment of it, any two-tier combination whose counts add past 15 works — the calculator below totals tiers live as you pick them. Treat 15 as a minimum: end pieces and uneven cuts always cost a few servings, and leftover cake has never been a problem.

Cake ordered or planned? The frosting calculator and recipe scaler handle the baking side if you're making it yourself.

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Frequently Asked Questions

What size cake do I need for 15 guests?

Cutting party slices (1½ × 2 in slice), a single 8" round seats about 20 — enough for 15. A single 7×11" sheet sheet (24 party servings) also covers it and is the easiest to cut and transport.

What size cake for 15 wedding guests?

Wedding slices are slimmer (1 × 2 in slice), so cakes stretch further: a single 8" round seats about 24. Wedding planners usually add a few servings of margin on top for cutting loss.

Should I round up for 15 guests?

Yes — treat 15 as the minimum. End pieces, uneven cutting and second helpings all reduce the real yield, so a size (or tier) above the exact fit is the safe choice. Leftover cake keeps; running short doesn't fix itself.