The cooking time for the turkey depends on the size of the turkey. A 12-13 lb. turkey will take about 4-1/2 to 5 hours. A 14-18 lb. turkey will take 5-3/4 to 6-1/2 hours.
The only safe method for determining whether a turkey is finished cooking is by testing it with an instant-read thermometer (compare prices). Do not rely on the turkey's pop-up timer (they aren't accurate). Insert the thermometer in the thickest part of the thigh.
The turkey is ready when the instant-read thermometer registers at 165 degrees F.
Important: Let the turkey rest at least 30 minutes before carving. This allows the turkey to retain its moisture.
Also, do not try to stuff a frozen turkey. Do not try to microwave a frozen turkey or thaw a turkey on the countertop. None of these methods is safe. Click here for more on how to cook a frozen turkey.