I am 5'4", 145 pounds, 34dd and ended up with the size small for reference. it fit well but definitely roomy - in case you're not into that style. never tried the extra small, but i would prefer this dress not to hug onto me so i stayed with the small. 

this dress was really nice and comfy, soft material. the pockets are low and my phone stayed in while i walked but i wouldn't recommend anything heavier than a phone to go in the pockets. 

i wore this to a family and friends function and re