Which size for Wings + Horns Loop terry Hoodie??

[leica2]

Hey guys I'm about to buy this size medium Wings + Horns Loop terry zi[ hoodie in olive/heather shown below. I'm 5'11 and a half with a 40-41" Chest and always wear a medium but I've never bought anything from W+H. I've heard there large is like a medium and medium is like a small. etc. etc. Anyone know if I should size up to a size Large for this hoodie or will I be okay with a medium? Just want to be sure as the store has a 20% restocking fee. Thanks in advance!

 

[Henryyy]

You're okay with the medium.