I have literally been stopped by strangers to ask where I got this sweater.  It is lightweight, which I like so I can wear indoors in office without getting too hot.  Based on other reviews I got a large (normally a medium) and it fit perfect.  The arms are small, not snug so if you are heavy in this area it may be tight.  The fit on me is as shown on the model.  If you have small shoulders such as a pear shape, this may run true to size for you otherwise I would order up one size.