According to Pen & Fork, 50 small side salads require approximately 50 cups of lettuce, while 50 entrée salads require 100 to 150 cups of lettuce. A head of Romaine lettuce yields 6 cups of cleaned and trimmed lettuce.
Pen & Fork recommends that chefs count on using 1 cup of lettuce per person for a small side salad and 2 to 3 cups of lettuce for a large salad that is served as a meal.
These measurements are for basic salads with only a few ingredients, such as sliced tomatoes, onions and cucumbers, Pen & Fork notes. Chefs preparing entrée salads with many ingredients can cut the lettuce portions used by half.