To find your best possible fit, we ask you to take the jersey or shirt that you feel fits you the best. Lay it flat and measure from armpit to armpit (PTP if you will) as shown in the picture. THAT'S IT. That's your size here at SFOD, whatever fit you want, THAT'S IT. When you choose your size from our drop down menu choose the measurement CLOSEST to that size. If it falls between sizes, you will have to choose to either size up or size down. The difference will be ~1 inch. If you like your clothes a little looser, choose to go up. A little tighter? Go down.  Easy!