I'm a size 6-8 and the medium black fit me very well.  Doesn't have a side stripe as many reviewers mentioned, which is fine.  The waist stripe which I thought may help with my little pooch is also thinner than the picture shows...  I'm thinking they either changed the product or the picture of the product is a completely different legging.  Overall, it's fine.  Although I think I prefer cotton leggings.  These are nylon.