Cycling Jersey Size Guide

 There is a lot of stretch in the fabric, for a "second skin" fit you can comfortably go a size down.

BODY MEASUREMENTS OF THE WEARER IN INCHES ACTUAL GARMENT MEASUREMENTS IN INCHES
 SIZE TO FIT CHEST SIZE 1/2 CHEST WIDTH 1/2 WAIST WIDTH BACK BODY LENGTH SLEEVE LENGTH
(FROM NECK)
3XS 32-34" 17.5" 14.5" 25.5" 13"
XXS 34-36" 18.5" 15.5" 26.5" 13.5"
XS 36-38" 19.5" 16.5" 27.5" 14"
S 38-40" 20.5" 17.5" 28.5" 14.5"
M 40-42" 21.5" 18.5" 29.5" 15"
L 42-44" 22.5" 19.5" 30.5" 15.5"
XL 44-46" 23.5" 20.5" 31.5" 16"
2XL 46-48" 24.5" 21.5" 31.5" 16.5"
3XL 48-50" 25.5" 22.5" 31.5" 17"
4XL 50-52" 26.5" 23.5" 31.5" 17.5