it is more correct to compare with the height:
(Unit：CM)
120=5T：Tops length=48 bust=84 shoulder=38 sleeve=14 Pants length=69 hips=88, fits for: 110-120cm height / 5 Years Old

130=6T：Tops length=51 bust=88 shoulder=40 sleeve=15 Pants length=74 hips=92, fits for: 120-130cm height / 6 Years Old

140=7T-8T：Tops length=54 bust=92 shoulder=42 sleeve=16 Pants length=79 hips=96, fits for: 130-140cm height / 7-8 Years Old

150=9T-10T：Tops length=58 bust=96 shoulder=44 sleeve=17 Pants length=84 hips=100, fits for: 140-150cm height / 9-10 Years Old

160=11T-12T：Tops length=62 bust=100 shoulder=46 sleeve=18 Pants length=89 hips=104, fits for: 150-155cm height / 11-12 Years Old

170=13T-14T：Tops length=66 bust=104 shoulder=48 sleeve=19 Pants length=94 hips=108, fits for: 155-160cm 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.