When hosting a small dinner party or gathering, one should plan to serve six appetizers per guest. For cocktail parties, 12 appetizers per guest is recommended.
Caterers use a formula to calculate the number of each appetizer to serve at an event. To calculate the total number of servings, they multiply the number of guests by 12, then divide that figure by the number of different appetizers being offered. If the appetizer is being served before a full dinner, then divide that total by two.
For gatherings of between ten and 45 people, six varieties of appetizer are to be served. For larger gatherings, caterers serve eight types of appetizer. For very small gatherings, they serve just three different types of appetizer.