I usually wear a size 4 or 6, either a small or medium in tops depending on style and cut. I ordered a small in this and it was definitely the right choice. I am 5’6” and 120 lbs. I am also long waisted. My chest is 34”, waist 28” and hips 38”. It’s casual and lightweight. Just looking at it I admit at first I wasn’t sure if I would keep it. But when I put it on I was totally impressed. It washed up well and I am looking forward to wearing it!