we order a size small but found we should have ordered a medium instead as they are a very good fit, the wife wore them on two occasions, and they did make a difference, have ordered some in medium size.
I was disappointed with these tights I purchased three pairs of the 60 denier previously and they are very comfortable but I found that the 20 denier were very short and difficult to put on I am 5' 1" they kept slipping down probably okay for someone shorter.