Food & Cooking⏱ 5 min read
How to Calculate Food Quantities for a Party or Event
Catering too little leaves guests hungry; too much means waste and expense. Here's a systematic approach to calculating quantities for every food type — from canapés to buffet mains.
Catering quantity planning is part science, part judgment. The science comes from reliable per-person benchmarks; the judgment comes from knowing your guests, the event format, and the time of day.
The Core Planning Variables
Factors that affect how much people eat:
Time of day: lunch portions ~80% of dinner portions
Event type: sit-down dinner > buffet > canapé-only
Duration: longer event = more food
Guest profile: mixed ages/children eat less than adults-only
Weather: cold weather = more food consumed
Alcohol: more alcohol = less food eaten (usually)
Number of courses: more courses = less per course
Per-Person Benchmarks: Proteins
Protein SourceDinner (main course)Buffet (one of several)
Beef joint (bone-in)250g raw / 180g cooked120g cooked
Chicken (bone-in)350g raw (1 thigh+drumstick)200g raw
Salmon fillet180-200g raw120g raw
Pulled pork180g cooked100g cooked
Sausages3-4 chipolatas or 2 thick2 chipolatas
Burgers (homemade patty)150-180g raw100g raw
Per-Person Benchmarks: Sides and Accompaniments
Side DishPer Person (dinner)Notes
Potatoes (roast)200g raw (3-4 medium)People eat more than you think
Rice (dry weight)60-75g dryDoubles in weight when cooked
Pasta (dry)75-90g dryIncreases ~2.5x when cooked
Salad leaves40-50gBulks up with dressing and toppings
Mixed vegetables150-200g preparedMore if only side
Soup (starter)250-300ml400ml as main course
Canapés and Finger Food
Canapés only (no dinner following): 10-12 pieces per person
Pre-dinner drinks canapés (1 hour): 4-6 pieces per person
Canapé-style wedding reception (3+ hours): 12-16 pieces per person
Rule: have at least 3 different types of canapé
Ratio: roughly 50% hot, 50% cold
Dietary: at minimum 25% vegetarian/vegan options
Sandwich platters (lunch, no hot food): 3-4 rounds per person
Mixed sandwich finger sandwiches: 6-8 pieces per person
Desserts and Cake
Birthday / celebration cake slices:
Standard sponge (25cm round): 18-22 portions
Sheet cake (30x40cm): 35-40 portions
Assume 80% of guests will have dessert (some won't)
Wedding cake:
Top tier: keepsake, don't cut
Second tier (20cm round): 20-24 portions
Bottom tier (30cm round): 36-48 portions (depending on depth)
Cheese board:
Mixed cheeses: 80-100g per person (end of evening)
As stand-alone course: 120-150g per person