All measurements are in inches and are approximate.

S M L XL XXL
Chest 19 21 23 25 27
Shoulder 18 19.5 21 23 25
Sleeve 19 19.5 20.5 22 22.5
Length 26 26.5 27.5 29 30

Chest - Measure across from pit to pit.
Shoulder - Measure across from the highest points of the shoulder seams.
Sleeve - Measure from the centre of the collar to the end of the cuff.
Length - Measure from the base of collar to the bottom of the hem.