I got these in a 2X for my mother, who wears a size 14.  Upon examining them, I realized that she would never fit into these--at least not without a real struggle (they do stretch a lot).  I then tried them on (I wear a size 10 in pants) and found that they fit me perfectly.  So I decided to keep them for myself.  They are comfortable, and fit like spandex shorts.  I plan on wearing them mostly with dresses--so my thighs don't rub together.  I recommend these, but make sure you buy much larger than you usually wear.