MosinelI got a medium shirt on the last tshirt drop (white/black poloroid tee, you can see it on the website) and I'm 5'10", 160lbs, size 40 chest. Its definitely a slim fit but not so much so that I can wear it. if you like slim fit stuff then a Medium will definitely work. It barely shrunk in the wash (though I wash on cold and dry with low heat). If you're tall or like a baggier shirt then I'd say get a Large