It fits true to size.. i have a rugby shirt in XL and it is a little big but not huge like a RIC and a sweater that is an XL but seems a little small.. and a pair of Jeans that fit perfect just a little long.
I'm 6'1 and I wear a L. It fits a bit small, but I don't like big shirts. I also don't put my clothes in the dryer so they don't shrink. Wash and hang dry. Your clothes will last you way longer that way... no fade, no wear.