I'm a size 16-18 in bottoms, I checked rhe size guide which says size 16 is XL in shapewear. I considered the fact that they might be slightly tight because I sometimes fit 18 better, but I figured because it is shapewear, that it will be stretchy material so should just fit and pull my tummy in a bit tighter. HOWEVER they don't even fit over my thighs, so I can't wear them at all. Sadly I have never returned anything before so I didn't think about that and I took the tag off so I will have to resell them. The material seems fine and it is true to the pictures, but the sizing needs to be re-evaluated.