How much food do you need for your party? You certainly don't want your guests to go away hungry, but you don't want to eat leftovers for a week, either. Here are a few adult portion size guidelines that may help you estimate how much to buy. Figure on eight-ounce portions of meat, chicken, or fish with the bone in, or four ounces if boneless. An ounce and a half is a serving of cheese. Three-quarters of a cup is an average serving of rice, pasta, or cooked vegetables. One cup is the standard serving size for raw fruits, vegetables, or salad greens. Allow three teaspoons of salad dressing per guest. If you decide to get ready-made party trays from the deli, the number of guests each will serve is generally listed. These are only general rules. Adjust them according to your guest list. A group of senior citizens or children may require smaller portions, but if you plan to invite a professional football team, you may want to invest in a whole steer.