This is the Dan Campbell era. 

Runs true to size. For oversized fit, order size up.

I am 5'10 170 lbs and wear XL for oversized and L for normal fit.

Not affiliated with nor licensed by any organizations. 

.: 100% ring-spun cotton
.: Medium fabric (6.1 oz/yd² (206.8 g/m²))
.: Relaxed fit
.: Sewn-in twill label