Approx guide for front lengths (from the shoulder) as follows:
XS (US size 2-4, UK size 6-8, European size 32-34) :
Front length 25ins (63cm)
S (US size 6-8, UK size 10-12, European size 36-38)
Front length 26ins (65cm)
M (US size 10-12, UK size 14-16, European size 40-42)
Frontlength28ins (71cm)
L (US size 14-16, UK size 18-20, European size 44-46)
Front length 29ins (73cm)
XL (US size 18-20, UK size 22-24, European size 48-50)
Front length 30 ins (75cm)
XXL (US size 20-22,UK size 24-26, European size 50-52)
Front length 32ins (80cm)
3XL ( US size 24-26, UK size 28-30, European size 54-56)
Front length 33ins (84cm)
Back length drops a further 2 ins