This is perhaps the most comfortable shirt I have ever encountered; you will definitely want to wash it before you wear it though. I am 6'0" and 158 lbs. I ordered the medium. It fits great. As indicated below, the sleeves are a little long, but that I believe is intentional---it facilitates the usefulness of the thumbholes. In any event, when I am not using the thumbholes, the sleeves are not noticeably too long.