Im 51 118 lbs 36B.  I ordered a medium. Length on this dress hits a couple inches above my knee.  Good fit in the bra area with extra room.  This dress has no waist definition so it hides any fluff, but will also be very cool in the tropics.  I wish I had ordered a small, but its not available in the Black with multi colored flowers.  Dress appears to be made well and the material  is a very nice and soft 100% Rayon.  I will try to gently shrink this via cold water washing by hand and then closely monitoring it in a moderate temp dryer.  Overall very cute and I like the V-back