The article provides information on how long it takes to cook a 20-pound turkey, whether it is thawed or stuffed. A thawed 20-pound turkey takes around 4 hours and 15 minutes to 4 hours and 30 minutes to cook at 325 degrees Fahrenheit. It is important to use a meat thermometer to ensure the breast meat reaches a minimum temperature of 165 degrees Fahrenheit and the dark meat reaches 175 degrees Fahrenheit. If the turkey is stuffed, it will need to cook for 20 to 25 minutes per pound, reaching an internal temperature of 165 degrees Fahrenheit.