it is more correct to compare with the height:
(Unit:CM)
130=6T:length=73 bust=98 shoulder=41 sleeve=46, fits for: 120-130cm height / 6 Years Old

140=7T-8T:length=77 bust=102 shoulder=42 sleeve=50, fits for: 130-140cm height / 7-8 Years Old

150=9T-10T:length=81 bust=106 shoulder=43 sleeve=53, fits for: 140-150cm height / 9-10 Years Old

160=11T-12T:length=85 bust=110 shoulder=44 sleeve=57, fits for: 150-160cm height / 11-12 Years Old

170=13T-14T:length=89 bust=114 shoulder=45 sleeve=61, fits for: 160-170cm height / 13-14 Years Old
Note:
1.There is 2-3% difference according to manual measurement.(1 inch = 2.54 cm)
2.All measurement in cm, please note 1cm=0.3937ch, 1 inch=2.540cm
3.Please check the figures carefully and order the right size, don't completely depend on the " age advice". It's just for reference.