I purchased this bra per the sizing instructions (size medium for a 34C) and it was waaaaay too small.  So small in fact that the large would likely be too small too.  This bra doesn't seem to be made for larger than a B cup size.  Not only were the cups too small, but there was a large gap between the shoulder strap and my chest.  Additionally, the thin straps were too short for me and dug into my shoulders.  A nicely made bra with soft fabric, but not for me.