I bought a large and medium, and both fit almost the same. it feels great while swimming, like it's not even there.
I love this rashguard. The first one I ordered the sleeves were too short although it was the same size as this one - large. I usually wear a size small or medium in a shirt but rashguards are so snug that I bought a large. I got the yellow one, it is very attractive on. I used it snorkeling in Mexico. It was great not to have to apply sun screen all the time.
