I'm 5ft10" with a medium build. After reading the reviews of this hoodie I decided to go ahead and purchase a size 1 up from what I normally buy. I bought the Large and it seems to fit me pretty well. When I hold my arms out in front of me the cuff of the arms sits right on my wrist if that gives you any indication. The hoodie is slightly slimmer in the body, but I didn't really notice it too much. It's a little hard to tell in the picture of the product, but the material is just like a normal sweater. When I saw the photos it looked like it was like a microfleece type 'fluffy' material, but that IS NOT the case. Anyway, good product but just be careful with the sizing.