i know there are only 2 sizes, i am a size 12 in jeans and ordered the L-2xl and it was a good fit, i wear spanx all the time and was very satisfied with this.  the only complaint i had that gave it 4 stars is that it could have been a little longer because i find my self tucking it back into my jeans alot.  i like the fact i wear my own bra with it and if i have a low cut shirt on it doesn't show the shaper