based on other people's reviews, i ordered a large. i am female, 5'7, 130-140lbs with toned fit. overall it fits perfectly. i was afraid the length might be short since it is youth fit but it comes right to my heels. it is a lot thinner/flimsy compared to the adult version of the product though but i don't mind as i use it for warm up before a work out; might be too cold to wear outside during the winter though-perfect for spring/fall weather.