LowRider, I measured from the top pf the shoulder at the seem down to the outside edge of the cuff, it's about 24 inches; I also measured from under the arm from the seem to the outside of the cuff, it's about 20 inches.
Note, the cuffs have Velcro adjustment to adjust the wrist size, a snap adjustment on the arm to adjust arm size, zip out liner, sealed seems, waterproof, vents etc. Well-made Can Am jacket. Yellow & Black size L.