As tough as it is in the AFC North, I feel like .500 is pretty good and would take that almost every year.
A good barometer to use is:
Win your home games (8-9 wins dep on conf rotation)
Win half your away games (~4 wins)
Losing a home game puts you in a hole in the away game category.
12 to 13 wins will put you in a good spot as far as conf seeding (maybe even #1 w/ bye).