Larger potatoes take longer but the average time is about 1 hour at 350 degrees. After an hour, squeaze the potato with an oven mit on your had (it will be very hot) and see if it gives easily. If so, it's probably done. If not, it should bake longer. If you're like me, you don't like to get to the middle of a potato and find raw bits. If you want to hurry the process you can run a metal skewer through the center of the potato before you put them in the over. This helps the oven's heat get to the center of the potato through the skewer. It should shave a good 10 minutes off the baking time.