I am 6'0" and weigh 200 lbs (with an athletic build).  A large fits me very well.  The sleeves are a bit tight, which I prefer.  There is enough room and length in the torso to fit someone who's 6'0".  If I was 6'2" I would probably need the XL.  The shirt is also very light weight.  I've worn it casually and in the weight room; it's great in both places.

I will be ordering more in different colors.