Small

Chest circumference measured at the armpit:

40" (101cm)

Zipper length:

24" (61cm)

Medium

Chest circumference measured at the armpit:

45" (114cm)

Zipper length:

25" (63cm)

Large

Chest circumference measured at the armpit:

49" (124cm)

Zipper length:

26" (66cm)

X-Large

Chest circumference measured at the armpit :

53" (134cm)

Zipper length:

26.5" (67cm)