It all depends on the number of guests you have, but a good rule of thumb is to estimate that each guest will eat about 4 oz. of candy. The formula to calculate this is the total number of guests multiplied by (four ounces) = total. For conversion to pounds, 4 ounces is equal to 1/4 of a pound. So, if you had 200 guests, you would have 50 pounds of candy.