I am 6'1", 130lbs...VERY tall and VERY thin.  I ordered the XL after asking the seller's advice and it was CRAZY big.  The arms were snug but you could've fit two of me in the width.  I tried to work with the seller to exchange it but, after 2 contacts, I got super-sick and wasn't able to contact them with some measurments they requested for a couple of weeks.  After that, they stopped responding to my questions amd just flat out ignored me.  Oh well...it will have to sit in the back of my closet until I either gain 100lbs or give it to a heartily-built dance friend (and I don't have too many of those.)  Very disappointing.  I'm not going to say I "hate it" because I would like it...if it fit...and if the seller would respond.  But it really is useless to me.  Maybe I will try to take 4-5 inches out of the back and fix it myself...there's a big seam running through the back anyway.