it is more correct to compare with the height:
(Unit：CM)
110=4T：Tops length=42 bust=64 shoulder=30 sleeve=39 Pants length=65 hips=68, fits for: 95-105cm height / 4 Years Old

120=5T：Tops length=45 bust=68 shoulder=32 sleeve=42 Pants length=70 hips=72, fits for: 105-115cm height / 5 Years Old

130=6T：Tops length=48 bust=72 shoulder=33 sleeve=44 Pants length=75 hips=76, fits for: 115-125cm height / 6 Years Old

140=7T-8T：Tops length=51 bust=76 shoulder=35 sleeve=47 Pants length=80 hips=80, fits for: 125-135cm height / 7-8 Years Old

150=9T-10T：Tops length=54 bust=80 shoulder=36 sleeve=50 Pants length=85 hips=84, fits for: 135-145cm height / 9-10 Years Old

160=11T-12T：Tops length=57 bust=84 shoulder=38 sleeve=52 Pants length=90 hips=88, fits for: 145-155cm height / 11-12 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.