How to Calculate Food and Drink Quantities for Any Size Event

Running out of food is every host's worst fear, while over-ordering wastes money and creates mountains of leftovers. The good news is that event caterers have been using simple rules of thumb for decades. Once you know them, you can confidently plan quantities for a birthday party of 20 or a corporate dinner of 300.

Start With the Key Questions

Before calculating anything, answer these questions:

1. How long is the event? Longer events need more food and drink.
2. What time of day is it? Guests expect a full meal at lunchtime or dinnertime, but lighter bites in the mid-afternoon.
3. Who are your guests? Teenagers and active adults eat more; older guests and children usually eat less.
4. Is food the main focus? A sit-down dinner needs different planning from a drinks reception with nibbles.
5. What is the weather like? Hot days increase drinks consumption considerably.

Canapés and Appetisers

Canapés are often the hardest item to estimate.

• Before a Meal: Allow 3 to 5 canapés per person for a 30 to 60 minute drinks reception.
• Drinks Reception Only (2 hours): Allow 8 to 10 canapés per person.
• Canapé Party Instead of a Meal (3–4 hours): Allow 12 to 15 pieces per person, including some more substantial "bowl food".

Main Courses

For a plated meal, your caterer will prepare one portion per guest, plus a small number of spares. For buffets and sharing-style meals, use these guidelines per person:

• Meat, Fish or Main Protein: 150 to 200g cooked weight.
• Rice, Pasta or Potatoes: 75 to 100g uncooked weight.
• Vegetables and Salads: 2 to 3 portions in total.
• Bread: 1 to 2 rolls or slices.

When offering several main dishes, reduce the portion size of each. Guests will usually take a little of everything, so plan for about 1.25 total portions per person across all dishes.

Desserts and Cake

• Plated Dessert: One per guest.
• Dessert Table: 2 to 3 small items per person.
• Wedding or Celebration Cake: One finger portion per guest if it is served as dessert, or half a portion if served in the evening alongside other food.

Ask your cake maker how many portions each tier provides, as this varies by size and shape.

Alcoholic Drinks

A reliable rule is to allow one drink per guest per hour, plus an extra drink for the first hour.

• Welcome Drink: 1 to 2 glasses per person.
• Wine With Dinner: Half a bottle per person, split according to your menu and guests' tastes.
• Toast: One glass of sparkling wine per person. A 75cl bottle gives six glasses.
• Evening Party: 1 drink per person per hour, with a mix of beer, wine and spirits.

In our experience at EMO, many venues and suppliers offer sale-or-return on unopened bottles, which takes much of the guesswork out of ordering.

Non-Alcoholic Drinks

Soft drinks are often underestimated, especially with more guests choosing not to drink alcohol.

• Water: Allow 500ml per person for indoor events and up to 1 litre per person in hot weather.
• Soft Drinks and Juices: 2 to 3 glasses per person over the event.
• Tea and Coffee: 1 to 2 cups per person after a meal or during a daytime event.
• Ice: Allow around 0.5kg per person, and double it in summer.

Offer at least one interesting alcohol-free option, such as a mocktail or premium soft drink, so that non-drinkers feel just as celebrated.

Adjusting for Your Event

Always allow a small buffer of about 5 to 10% for unexpected guests and bigger appetites. If your event includes children, count under-tens as half portions. For cultural celebrations with generous hospitality traditions, increase main course quantities. An experienced caterer will help you refine these figures for your guest list.

Final thoughts

Calculating food and drink quantities does not have to be guesswork. Use these per-person guidelines as a starting point, adjust for the length, time and style of your event, and add a small buffer. You will avoid both empty platters and wasted food, and your guests will leave well fed and happy.