I just measured the arm and I got approximately shoulder to cuff 24 inches and from top of the arm to cuff approximately 21 inches maybe 21 in a half I hope this helps I not really sure how to exactly measure the arms.
This jacket is for both fall and winter it is not a light jacket or a heavy jacket unless you live where you get a lot of heavy snow this can be used sorry you were confused, this is a very cute adorable jacket that looks even cuter while wearing thank you and good luck.