I bought these to wear with long sweaters and boots. I'm 5'4" and 117 lbs and as I don't like skin-tight leggings I went with the medium. In retrospect I probably should have ordered the small but the medium is comfortable. The only thing to be aware of is that these are really low cut and I keep feeling like I have to pull them up. If you have any kind of tummy bulge and want to wear these with any tighter tops they may not be the leggings for you as the low waist could result in the dreaded "muffin top." Material is nice and thick and they didn't shrink much when I washed and dried them in the dryer.