Boxy fit, take your true size.
S- 43" chest, 25.5" length, 24" sleeve, 44" opening at bottom
M- 45" chest, 26" length, 25" sleeve, 46" opening at bottom
L- 47" chest, 26" length, 25" sleeve, 48" opening at bottom
Model is 5'8" tall and is wearing a size Medium