How many people does a cake feed? It depends on the size of the pan, the height of the cake and above all the size of each slice: a wedding slice is half the size of a party slice. This calculator works from the top surface and height of the cake to give a realistic number of servings and the number of cakes you need.
Standard serving sizes
| Serving | Size (for a 4 in tall cake) | Surface |
|---|---|---|
| Wedding | 1 × 2 in | 2 sq in |
| Buffet | about 1.25 × 2 in | 2.5 sq in |
| Party | 1.5 × 2 in | 3 sq in |
| Generous | 2 × 2 in | 4 sq in |
These sizes assume a standard layer cake about 4 in (10 cm) tall. A taller cake gives proportionally more servings because each slice can be cut thinner; a single 2 in layer gives about half.
How the calculation works
- Top surface: π × diameter² ÷ 4 for a round cake, side² for a square, length × width for a rectangle
- Servings = surface ÷ serving size × (height ÷ 4 in), rounded down
Example
An 8 in round cake has a top surface of about 50 sq in. At 4 in tall it gives 16 party servings, 25 wedding servings or 12 generous ones. For 30 guests at a birthday party, plan 2 cakes of that size, or one 10 in round (about 26 servings) plus a small cake.
Typical numbers
| Pan | Party servings | Wedding servings |
|---|---|---|
| 6 in round | 9 | 14 |
| 8 in round | 16 | 25 |
| 10 in round | 26 | 39 |
| 8 in square | 21 | 32 |
| 9 × 13 in sheet | 39 | 58 |
Cutting tips
- Cut round cakes in a grid rather than in wedges to get many even servings: cut a circle about 2 in inside the edge, slice the ring into pieces, then repeat on the inner circle.
- Use a long, thin knife dipped in hot water and wiped between cuts.
- For tiered cakes, add up the servings of each tier; the top tier is often saved.
- Plan a little extra for hungry guests or a sheet cake kept in the kitchen.