I am pleasantly surprised by the fit, it is not easy to find the perfect combination of Asian style and American style. I'm slim but muscular. Having said that the 'smallest' sizes fit me best, Asian styles seem to be moving to large sizes lately as US sizes are also getting bigger BUT this size seems to be the norm. I actually ordered more shirts in other colors. These are the moisture wicking shirts I use when cycling outdoors. They keep me cool and dry. A tiny thinner is worth noting; The sleeves seem a little short, if they were say an inch longer they would get 5 stars. When cycling, the sleeves rise slightly above the middle of the bicep.