it is more correct to compare with the height:
100=2T-3T：dress length=58 bust=58 waist=56; fits for:90-100cm height / 2-3 Years Old

110=4T：dress length=63 bust=60 waist=58; fits for:100-110cm height / 4 Years Old

120=5T：dress length=68 bust=64 waist=62; fits for:110-120cm height / 5 Years Old

130=6T：dress length=73 bust=68 waist=66; fits for:120-130cm height / 6 Years Old

140=7T-8T：dress length=78 bust=72 waist=70; fits for:130-140cm height / 7-8 Years Old

150=9T-10T：dress length=83 bust=76 waist=74; fits for:140-150cm height / 9-10 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.