I bought these in an xl since the women's union suit doesn't come in plus sizes. I wear a 3x. They are fitting around my large calves and it's loose on the body. it's perfect and toasty warm.
You won't want to take this off once you climb into it. Recommend having at least 2 suits so you won't be without one on washday. It's like a second skin.
My husband needs warm clothes, as his work takes him outdoors during the harsh New England winters. He requests (and gets) these every year when it gets cold (and also for the holidays as gifts) as no other brand or item will do.