Lay the jacket flat on its back. Pull the sleeve straight out to the side. The measurement should be 1” from the armpit up to the top of the sleeve, in a line that is perpendicular to the top of the sleeve.

Lay the jacket flat on its back. Pull the sleeve straight out to the side. The measurement should be 1” from the armpit up to the top of the sleeve, in a line that is perpendicular to the top of the sleeve.