As I recall, if you start with a frozen turkey, you should use the following formula: 24 hours of defrosting time (in the fridge) for every 4 pounds of turkey. So, a frozen 16 pound turkey would need to defrost in the fridge for four days. Of course, you can use water to defrost a turkey more quickly.
You thaw turkey in the fridge!!!! Mine is in there as we speak! It takes 3-4 days or more depending on the size! Put it in the fridge now and you'll be okay! Never on the counter, unless you wanna spend the holiday in the ER!