I am 5'10" and 170 lbs. At first I ordered a medium but ended up sending it back and bought a small instead. I usually wear a medium or large size but the medium size it came out I bulged. The photos I uploaded are small. I love the stretchy material it reminds me of my sport polo shirts under the armor. I like my shirts to be snug. The shirt is very comfortable and I love the fabric that it's made of. I would definitely buy this shirt again.