I am 5'7" 180lbs, so I am a size large in almost all tops. So I ordered a large. I was shocked at how huge it was. The cut is ridiculously wide and boxy. I exchanged it for a medium. It fits better, but it's still a bit loose fitting all over, especially in the arms, and my arms aren't small. Not sure it's flattering on me. It's a thin sweatshirt but with a high % of synthetic fabric, so it is quite warm. The fabric is smooth, stretchy and " sporty". Not sure if it's practical. I am disappointed overall.