Height: 5'9", Weight: 160lbs, pant size: 31x30, inseam 28.5". I normally wear size M in everything and these fit me perfectly. These Tiro 17 pants in size S seem to fit me very well with a tiny bit of breathing room. Definitely not too tight with some room in the thigh area. Waist stays in place without having to the it. I can still pull the elastic waist  out a few inches. The material is like a soccer jersey material, not like cotton sweats. Very happy with them so far. I would definitely like to order other colors.