At the price backcountry is blowing these out for, this is a no brainier. Just got my large suit the other day, and it is amazing. I am 6'0 180 and the large is a good fit. Even for friends who are 5'9 and up, as long as you have 165 pounds on you or so a large will fit finewithout being too baggy. Just use the sinch in the middle and tie up the waste nice and snug. Loved my suit so much I just ordered another in a different color. Anyone who knows anything about merino wool knows 50 dollars will normally buy you a short sleeve shirt, not AN AMAZING BASELAYER SUIT. At first based on other reviews I was worried when there wasn't a medium size left, but am glad that was the case and I got a large, very comfortable, and a steal at the price. Can't wait to take it to the mountain this winter!