A buffet line · Saile Ilyas
Food quantity calculator
Estimate total food quantities from guest count, service style and event length.
Estimate
Quantities are planning weights, not serving sizes: they include the margin caterers leave so that nothing runs out. Adjust for your own menu and your own crowd.
What this assumes
- Base plate of 170 g protein, 140 g starch and 140 g vegetables per adult, before adjustments.
- Buffet and family style add 12 to 15 percent because guests serve themselves.
- Events longer than three hours add 5 percent per extra hour, up to three hours.
- Children are counted as half an adult portion.
- Alcohol adds 5 percent.
These are estimating rules of thumb, not guarantees. Check the numbers against your own menu, your own staff and your own suppliers.
Related reading
GuideService styles comparedBuffet, plated, family style, stations and passed canapes, and what each one does to your staffing, your timing and your food quantities.
GuidePortion planningThe per-guest figures caterers work from, what changes them, and where they go wrong.
GuideStaffing an eventHow many servers, bartenders and kitchen staff an event needs, and the hours nobody counts.
Page revised 18 September 2026.