All my sport shirts are small. But this little one is like a children's environment. I choked on it. Seriously, it was like wearing a corset. I like the shirt but next time I'll have to go up a size. Okay I just read another guy's review and he said he's 2 inches shorter than me and weighs 15 pounds. lighter than me and went with medium. I wish I had read this review before buying mine. Oh now I know.