I am 5'8 and weigh 140. I ordered a 6 and an 8. The 6 fit perfectly. (I wear a size 28 jean, and a C cup). It looked fabulous on, and I got a million compliments. The fabric flows beautifully, and is very flattering. Thank you RTR! As far as RTR goes, if this is your first time ordering and are skeptical, have NO doubts...they ship it promptly, send it with an envelope..and it came perfectly pressed and clean with a really cute garment bag. I would easily recommend this to anyone looking for that special dress for any occasion! Thank you!!!