I wear a 12 pencil skirt and dressy pants but have some extra tummy.  I bought a large in this and nearly passed out trying to get it on.  It's not a silky, smooth fabric like other Dr. Rey shapewear I've bought and really liked.  This is a rough, itchy, thick knitted material.  The panty part seems sized fairly, has much less firming capacity, and is comfortable enough......the top portion is unbearably tight and constrictive and rolls down badly.  I'd reach under my clothes and pull it up with great effort and it was rolling down like a window shade at my first breath or movement.  If I bought another one (I won't), I'd size up at least 2 sizes.  I tried to wear mine Christmas Eve while exchanging gifts with immediate family.  I managed to keep it on about an hour before heading for privacy and yanking it off.  I now have the "hold-your-belly-in" portion stretched around a huge vintage pickle crock where I am trying to "enlarge" it to a wearable, bearable size. You get what you pay for.  This was only 13-14 bucks and not worth the the postage or fighting Amazon about a return of a worn undergarment.  Compared to some shapewear, I'd give it a C-.  Compared to other Dr. Rey shapewear, I've give it an F-.