These tights are a great study material that I'm sure will hold up, but the sizing is not true at all. I always wear smalls, but since I like the waistband a bit looser (leotards look nicer without seeing the band cutting into your sides), I decided to order a medium this time around. I was very disappointed that the waistband was a separate stiff piece of elastic instead of a continuation of the tights, and very tight! I ordered a medium, though I'm only 5 feet tall and 105 pounds. If I were to order these tights again, I would get a large even though I am so petite. (Note, these tights fit tighter on me that some children's tights that I own)