A stuffed turkey will take about 20 to 22 minutes a pound to cook in a 325 degree oven. A stuffed turkey will take around 5 minutes per pound longer to cook than an unstuffed bird.
While this timeline is fairly accurate, it is best to check for doneness using a meat thermometer since oven temperatures may vary. Place the thermometer in the thickest part of the thigh without touching the bone. When the temperature reaches 180 degrees the turkey is fully cooked. Also check the stuffing temperature by inserting the thermometer in the center of the stuffed cavity. When that temperature reaches 165 degrees the stuffing is done.