XS  S  M L
Chest 19.5" 20.5" 21.5" 22.5"
Sleeve Length 22.5" 23" 23.5" 23.5"
Shoulder Width 16.5" 17" 17.5" 18"
Body Length 27.5" 28.5" 29" 29.5"
Collar Girth 18.5" 18.75" 19" 19.25"

*Model is 1.77m and wears size S. Model wears size M in 3rd photo.

There's allowance at the chest and waist. You may stick to your usual size for a relaxed fit or size down for a slimmer fit.