I usually wear size S or M depending on women's height. I was having trouble finding a skeleton sweater for a while so decided to give it a try. Size XXL is great. I could probably go for size XL, but since it's 100% cotton, it's probably the best choice. I'm 5'10", so I'm glad the sleeves are even long enough! It's quite high quality and heavy for the price; the front is double layered as others have said so you can even turn it inside out for x-ray vision can wear.