I am a fairly thick woman, 5 ft, 175 lbs, usually a size large in leggings. I didnt want to risk them needing to stretch too much because I didn't want them to become see through, so I ordered up a size as other reviewers suggested and they fit perfectly. They are even squat proof! (I tested it in a bright bathroom, so believe me, as long as you order the right size and they aren't too small and stretched to the max, they are NOT see through!