Usually shirts shrink about one size. A 4xl would probably shrink to around 2.5. It pisses me off when I buy my clothes too big. I had an ecko sweater that was big and thick and costed like 80 bucks but I've worn it only 3 times in a year cuz its so big.lol....i think it has shrunk a bit since i washed it lol
just say 2.5 //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif people will know what you meanok ill say the tag says 4x but maybe a 3 now lol