Google maps says it is five and a half hours although in my driving experience it only takes four and a half to five hours. It's 335 miles.
The total distance from Nashville to Auburn is about 1966 miles or 3162 kilometers. This distance is equal to 1708 nautical miles and an average flight takes 3 hours and 56 minutes to cover this distance with an average speed of 500 mph, which is equivalent to 805 km/hr or 434 knots. If you are planning a road trip then you can cover the same distance in 35 hours and 45 minutes with an average driving speed of 55 mph or 88.5 km/hr.