I just received my jacket, size Medium. I'm 5'7", and I weigh 170lbs with a 42in chest, and the medium is a great fit. I would say that the medium will fit someone up to 5'10, 180, because there's a little play in my jacket. The jacket is of great quality.it's waterproof, cinch tabs to pull it in at the waist, velcro tabs at the wrists, plenty of pockets, and fleece lined. I ordered the tan, and once I received it and tried it on and saw how good the quality was.I immediately ordered a green jacSee full review