I bought these mostly because I thought they looked silly and I love silly pants. I did not expect them to be so comfortable and high quality. The waistband has a couple of buttons so you can customize the size, but I still like wearing it with a belt for added support. I am 5’10” 155lbs and a medium fit pretty well. I might be able to squeeze into a small, but I don’t want to put myself through that. My 5’11” 200lb boyfriend can also fit into them comfortably if I adjust the waistband, so I hope that gives a reference for how versatile the sizing is. I can tell that this is made to last, and I cannot wait to have them for many more years.