This fleece is so cozy! I think it runs a touch big (by one size). I got a medium, but could have probably gotten a small and still had room for a layer or 2 underneath, but it was a final sale item. I still love it because since it's on the larger side I can pair it with leggings and go for the looser/baggy look on top. For reference I'm 5'8" 150# athletic build.