my son measures 32 inch chest. I thought he would need the xsmall, but it didn't come in that size, so I ordered the small, thinking it might be a little large on my very skinny boy...it was tighter than a second skin, it pulled across the chest and made it hard for him to move his arms. It was also so short that it would definitely ride up. He loves the look of it, but I don't think a medium will fit much better--there's no way to judge--and I am not interested in paying return shipping repeatedly. Very disappointed, but should have guessed: Hurley's sizing is very different from everyone else's.