Patagonia Men's Top Size Chart

Size	Chest	Hip	Arm Length
XXS	33 in	32 in	30 in
XS	35 in	34 in	32 in
S	37 in	36 in	33 in
M	40 in	39 in	34 in
L	44 in	43 in	35 in
XL	47 in	46 in	36 in
XXL	50 in	49 in	37 in
XXXL	56 in	55 in	37.5 in

* Chest is usually the best size predictor. However, if your hip measurement is larger, consider buying the size indicated for your hips.