Just bought this for my Easter Dress and possibly also to be worn in a 50's style play that I am in.  I am a comfortable size 14( meaning I do not lean closer to a size 16 or a size 12) and a 38DD chest.  I got an XL.  I was wearing a minimizer bra when I tried the dress on, but it fit perfect and was not too snug across the chest nor did the holes around the arms gape from my chest. I am sure if I wear  it with a normal bra it will fit just fine as the bodice material is stretchy.  Contemplating getting a petticoat to go with this to make it more flirty, but my husband said it looks fine without one.  It is rather plain, so make sure you have some fun jewelry to snap it up with!