The other thing to bring into consideration is what are doing with the skis...
You will want big mountain powder skis to be in your upper length range.
Most folks like a park skis that are a little shorter.
For example my powder skis are 189s, but my park skis are 174s. My old Hart F17s (comp bump skis) are 167s.
181 is probably a good all mountain size for you at your current weight .I might even go bigger if you are thinking about big mountain stuff. If you are thinking mainly park, I would steer you more in the 175ish range.
Camber, Rocker, early rise, and weight to lesser extent will also change how long a ski feels. Unfortunately it is not as simple as it was back in the straight ski days...
Finally, since you are only 16, you probably will put some muscle on as you get older, so erring a little too big is probably the right way to go.
