I'm 5'7"/165 lbs and bought the chambray blue shirt in size medium for a summer trip. It was slightly large for me (good in the shoulders but a little baggy), but still fine, and very comfortable and casual. I liked it so much I ordered the maroon in a small, and it fits almost perfectly, slightly snug in the shoulders, and a perfect fit for the body. I wore it for the first time last night and I received several compliments on how nice the shirt was. It's extremely comfortable and soft. The only con I can think of is if you're sweating, it shows the sweat pretty badly. I like how the shirt is both casual but also slightly dressy. The color and texture to it is very nice.