I'm 5'7 and 137 pounds and i tried on this dress in the store. i got the small as it has a little more material in the medium and the small fits like a glove. this dress is great quality and feels good, looks good and can be dressed up or down. like the model in the picture i like the flats with this dress. high quality fashion and total comfort on a hot summer day. go anywhere with this dress and you look like a million dollars. one more little hidden detail it has a detachable slip underneath