I ordered an XS in navy. I'm 5' tall and weigh 110 lbs. The sweater fits comfortably with room to spare. If I gain 10-15 lbs, it will still fit fine. This sweater is incredibly soft and well made. The weight and weave of the yarn won't keep you warm in really cold weather. I'd consider it mid-weight and it's perfect for keeping me from freezing in the frigid AC of my office. The photos on Amazon make it look like it has a sheen to it, but it does not. It looks and feels much more expensive than it is. I wish this came in some summer colors because I would definitely order one or two more if I had more color options.