Q. I am having an outdoor barbecue for about 70 people. I am serving chicken, hamburgers, hotdogs and ribs. I am also serving appetizers, salads, veggies, and desserts, and I really do not know how much of each item to purchase. Is there a rule of thumb for calculating how much food per person overall?
The rule of thumb is to have enough, even if that means having too much. It's amazing the quantity of food 70 people can go through in a very short time. People also eat more when they have the opportunity to serve themselves and quite often take more than they can eat, so you need to be prepared. Good caterers have developed this into something of a science, and take into account such things as the average age of the guests (reasoning that older guests are wise enough not to overeat), how many of the guests are single (and tend to eat out of cans generally, so will go wild at the sight of a home-cooked meal), the time of day, etc.
As a general rule, figure on 8 ounces of uncooked meat or fish (excluding the weight of bones), a cup of starch, half to two-thirds of a cup of vegetables, a cup of salad, and a roll and a half per person at a buffet. Figure on only two-thirds of those amounts for smaller children, but double them for teenagers. Then factor in a few phantom guests, to be sure you have enough and to spare.
We always turn to the Food Quantity Chart in Nicole Aloni's Secrets from a Caterer's Kitchen (Canada, UK) for help in estimating how much to serve at parties.
Based on the assumption that there will be two entrées, two or three vegetables, two or three salads, bread, and two or three dessert choices, Aloni has calculated a chart that provides a half-size portion of each dish for every guest (since you plan to serve four meats, you should cut those figures in half). The quantities are for the raw and untrimmed weights of the ingredients. For a buffet for 75, she suggests mixing and matching the dishes you want from the following: