I wear a 34DD and bought a medium. The FIT is very comfortable, stretchy, and somewhat supportive. This bra would be fine for walking around in, but I wouldn't exercise in it. However, the stitching at the top of the straps is VERY itchy! I am returning it for this reason. I couldn't wear this for more than a few minutes without feeling like the tops of my shoulders were going to be scratched to death.