Serving Size Calculator
Work out how much food to buy for a given number of guests.
Please note: An estimate based on the figures you entered. Real-world results vary with conditions this calculation cannot see, so treat it as a starting point rather than a final answer.
What the Serving Size Calculator does
Catering quantities come from a portion per person multiplied by the guest count, then padded for trim and waste. The portion itself depends on both what the food is and how it sits in the meal — a main protein needs far more per head than a side.
Formula
Total = Portion per person × Guests × Appetite factorWith waste: Total × (1 + Waste %)Cost = Total kg × Price per kg
Inputs explained
| Input | Unit | Required | Notes |
|---|---|---|---|
| Number of guests | number | Yes | Accepts 1 or more. |
| Food type | one of 11 options | Yes | — |
| Custom portion per person | g | Optional | Overrides the choice above if set. Accepts 0 or more. |
| Appetite | one of 3 options | Yes | — |
| Allowance for waste and trim | % | Optional | — |
| Price per kilogram | selected currency | Optional | Accepts 0 or more. |
| Currency | one of 10 options | Optional | — |
How to use it
- Choose Food type and Appetite.
- Enter Number of guests.
- Optionally add Custom portion per person, Allowance for waste and trim and Price per kilogram.
- Select Calculate.
Worked example
Twenty guests, boneless meat as the main course, 10% waste allowance.
- Guests
- 20
- Food
- Meat, boneless (200 g)
- Waste
- 10%
200 g × 20 = 4 kg, plus 10% for trim gives 4.4 kg to buy.
Frequently asked questions
How much meat per person?
About 200 g boneless or 350 g bone-in for a main course. A whole roast bird needs around 500 g per head because of the carcass.
Should I cater differently for a buffet?
Yes — reduce each individual dish by roughly 20% but offer more variety. Guests take smaller portions of more things.