So I always have a challenge with sizing. I am tall (6'2") but thin (180lbs). I am one of those in between size types. Luckily I prefer things to be a little loose so going with the large works out as long as I am using it in the winter and have insulation on underneath. A medium would be a more alpine fit, but then the sleeves would be on the short side and the jacket too tight with insulation on underneath. But the stretch is nice when extending the arms and the breath-ability is on par with most breathable jackets...don't push it too hard and sweat.