“I’m 5’9” and we 174 and muscular with a small waist. The shirt runs big. I ordered the medium and it fit me like a large. It would have been fine but for this style of shirt I wanted a snug fit across the shoulders without being too small at the waist and that’s what I got with a small. I normally wear a medium in most cases. I have a few of the backwoods flannels that fit me perfectly in a medium for comparison. It’s a good, comfortable shirt that holds its shape well. I’d buy again.”