I bought the medium, 5'5" 150 lbs, and it fits perfectly. The button and crossover piece are lovely and add to the vibe. It is very comfortable and classy LOVE IT!
At first I was disappointed when I got this sweater because I expected it to be a bit heavier. But the more I looked at it and tried it on, I began to really like it. It's not too hot and very stylish!