Hatfield and Smithfield Farmland suggest heating a fully baked ham approximately 15 minutes per pound. The size of the ham may require shorter or longer cooking times.
Both Hatfield and Smithfield Farmland suggest covering the ham with aluminum foil while it is heating. Remove all of the packaging of the ham, and place the ham in a shallow dish. Ham with the bone intact requires covering the ham loosely with aluminum foil and may require adding five minutes per pound for thorough heating. To heat a fully cooked ham in a microwave, cut the ham into half-inch slices, and heat the ham at 50 percent power in the microwave for approximately 30 minutes.