I'm 6ft 0.185lbs, waist 32", chest 42". I ordered L. Material 92% polyester/8% Spandex. Works for me. It's very thin in the chest and shoulders, but not too tight around the waist. The neckline is a bit wide with a deep V-neckline, but that doesn't bother me. That's bad. Due to the synthetic fabric, it pulls expose this shirt to the sun's rays and you will be very hot in it on the street.I haven't washed it yet but the fabric feels fragile and I doubt its durability.The length is a bit short because it's just below my waist so it opens up when you fold it Finally, to reiterate, this shirt hugs the chest and shoulder area very well, so if your pecs and trapezius muscles aren't up to par, this shirt obviously will in. EDIT: I ordered the black crew neck in L and it arrived today. It's made from a cotton blend instead of polyester and spandex and has a looser fit. Cotton feels cheaper than synthetic, the sleeves have a cheaply sewn hem rather than a well-pleated hemline, and it just doesn't fit or is as good as heather black. I'm sending it back today.