I ordered this rashguard to avoid sunburns while swimming with my kids.  I usually manage to miss sunscreen on my back somehow, or I'm just too pale, lol, so I figure this will help.  The size is nice.  I'm 5'4" and 133lbs.  Just a B bust.  I ordered the size USA Large, and it fits well.  It's not skin tight but not baggy either.  There's comfortable room to wear it over my swimsuit.  I feel that I can move my arms all around with no discomfort or fear of ripping a seam.

Oddly enough, this rashguard can look different colors in different lights.  The packaging calls it "neon yellow," which is precisely what I saw when I first opened the package.  I was surprised, but since I wasn't buying it to match anything else, I didn't mind.  Then in another setting, the color actually looked green like it did online.  Sort of odd, so I figured I'd mention it here.