I wasn't sure what to expect when I ordered, so I ordered one size larger. I normally wear a Large, but ordered an XL.The fit is somewhere between those two sizes and is very comfortable. It is also surprising warm for such a light weight shirt. I just ordered another one in a different color.If I have anything to complain about, it would be that there needs to be more color choices, like a light blue, and a yellow, and an orange.I do recommend the purchase of this item.