The average size of a dinner serving of boneless spiral cut ham is between 1/4 and 1/3 pound. Servings of partially de-boned hams are slightly larger at 1/3 to 1/2 pound. For bone-in hams, the size increases to between 1/2 and 3/4 of a pound.
A host must consider the appetites of the guests when deciding how much ham to serve. If there are many children present, for example, the average serving size may be considerably smaller. In general, a 7-pound ham feeds about twelve people as a main course or sixteen to eighteen people when served on a buffet.