I'm 5-8 and about 160 lbs and ordered a small. Its just the right size. Im by no means slim, and its a good fight, if not slightly tight, but a good tight. I was a little surprised it fit so well because the golf pants and chinos are pretty darn big. I had to order 1 size down (i would;ve done 1.5 sizes down if i could) because they were so big at the pants and waist. its a pretty light shirt and feels like it was made with quality. This shirt is a little more purple than the pictures but i won't dock stars off for that. just an observation. Will order other shirts when i have coupons or when they have sales.