The estimated cooking time for a spiral ham is 20 to 30 minutes per pound. This cooking time is used when the ham is cooked in an oven heated to 325 degrees Fahrenheit.
If cooking a whole spiral ham, it should be placed in a roasting pan with the fat side facing upwards. If a half or quarter ham is being prepared, then it is recommended to cook it with the flat side facing down.
The ham should be covered with aluminum foil when cooking, and it should be allowed to rest for 20 to 30 minutes once removed from the oven.
If the ham only needs to be warmed, the cooking time is 15 minutes per pound in an oven heated to 275 degrees.