Let's talk about cooking time and internal temperature when you're learning how to bake a ham in the oven. Always be sure to look at the packaging instructions for your specific ham, and follow what it says for cook time. This spiral ham came from Aldi, and it said 12 to 15 minutes per pound. So being a 10-pound ham, it needed to cook for about 2 hours (120 minutes) or more, but not too long or it'll dry out. An 8-pound ham would take about 96+ minutes to bake. A 12-pound ham, 144+ minutes. And so on and so forth. According to the USDA, spiral-cut cooked hams that were packaged in processing plants under USDA inspection must be heated to 140 °F as measured with a food thermometer (165 °F for leftover spiral-cut hams or ham that has been repackaged in any other location outside the plant). Cook-before-eating hams or fresh hams must reach 145 °F (with a 3-minute rest time) to be safely cooked before serving. Read more of their Ham and Food Safety instructions.