Wedding Cake Size Calculator
Calculate wedding cake tier sizes and total serving count from guest count and portion size.
Returns tier diameters for 2, 3, and 4-tier cakes.
How Wedding Cake Size Is Calculated
Wedding cake sizing ensures every guest gets a proper serving without wasteful excess. The standard calculation is based on serving portions per tier.
Portions per Tier (standard 4" tall tier):
| Tier Diameter | Round (portions) | Square (portions) |
|---|---|---|
| 6 inch | 12 | 18 |
| 8 inch | 24 | 32 |
| 10 inch | 38 | 50 |
| 12 inch | 56 | 72 |
| 14 inch | 78 | 98 |
| 16 inch | 100 | 128 |
Standard wedding slice: approximately 1 inch wide × 2 inches deep × 4 inches tall.
Worked Example: 150 guests, round tiers:
- Option A: 6" + 10" + 14" = 12 + 38 + 78 = 128 portions ✓
- Option B: 8" + 12" + 14" = 24 + 56 + 78 = 158 portions (good buffer)
Planning Rules:
- Order for 10–15% more than guest count (late additions, extra helpings, staff)
- Not every guest will eat cake (children, dietary restrictions): order for ~85–90% of guests
- Cutting cake into smaller slices is common practice — 1"×2" portion per person
Tier Stability:
- 2 tiers: suitable up to 80 guests
- 3 tiers: 80–180 guests
- 4 tiers: 180–250 guests
- 5+ tiers: 250+ guests or decorative display (add sheet cake for serving)
Flavors by Tier: Offering 2 flavors (one per pair of tiers) satisfies more guests than a single flavor for the entire cake.
How we build and check this calculator
This calculator runs entirely in your browser, so the numbers you enter stay on your device. The math behind it is written by hand and tested against worked examples and standard references before the page goes live.
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