Approx measurements (when jacket laid flat):

24″ Under arm to under arm 18″ Length from nape of neck to bottom 21″

26″ Under arm to under arm 19″  Length from nape of neck to bottom 22″

28″ Under arm to under arm 20″  Length from nape of neck to bottom 23″

30″ Under arm to under arm 21″ Length from nape of neck to bottom 24″

32″ Under arm to under arm 22″  Length from nape of neck to bottom 25″