I made mine on high and it took just 5 hours to cook. Cooking time can vary depending on your crock pot or slow cooker. So I usually say 4-6 hours on high or 6-8 on low.  Just check an hour or so before hand and check if the chicken is cooked through. The internal temperature of the chicken should be 165°F. However I like when the chicken is fall apart tender and you should be able to see that without a using a meat thermometer.