I have a size 35"-36" waist and I'm 5'10"  185 lbs. I ordered a medium. It's a bit loose in the buttocks. I think a small would've worked better. I have a testicle injury so the tighter the better when the pain falres up as I've has one surgery with this type of pain. The fabric and how these briefs are made are better than previous Briefs I've bought from Hanes. I like boxers better but the older I get, the bigger things seem to get, so tighter for me is better. I give it four stars because they are well made and deduct a star because the sizes cover too much of a range of waiste-lines.