absolutely love these! I am 125 lb, have a 24 inch waist, athletic build and ordered a Large. I am a small in pants always and depending on the brand, almost always a small in bikinis as well. The large definitely fits snug, but i like that. If you have any loose skin or a little pooch, I could see these giving major love handles. I agree with all the reviews saying to size up two sizes! i also love the stitching and quality because they stay in place, i don't have to worry about my butt eating them when i walk.