Size Chart Using the Size Chart as a reference, a size up or down from there (if necessary) will get you to the right fit. -------------------------------------- Size-------------Age----------------Chest Length -------------Length 70cm----------0-3 Months----------48cm/18.9"------------37cm/14.6" 80cm---------3-6 Months---------50cm/19.7"------------39cm/15.4" 90cm---------6-12 Months--------52cm/20.5"------------41cm/16.1" 100cm-------12-18 Months--------54cm/21.3"------------43cm/16.9"