5’7”, 165lbs, 30in waist, athletic build. I ordered a medium. The quality and material seems pretty good. They fit perfectly around the waist. man they are shorter and tighter than expected. Like so short that my briefs hang out of the bottom. bought these for leg day but I don’t think I can wear them to the gym. Certain exercises may expose too much. I would recommend a size or two larger than you think.