it is more correct to compare with the height: 100=3T：length=58 bust=60 ; fits for: 90-100cm height / 3 Years Old110=4T：length=63 bust=64 ; fits for: 100-110cm height / 4 Years Old 120=5T：length=68 bust=68 ; fits for: 110-120cm height / 5 Years Old 130=6T：length=73 bust=69 ;f its for: 120-130cm height / 6 Years Old140=7T/8T：length=78 bust=72 ; fits for: 130-140cm height / 7-8 Years Old150=9T/10T：length=83 bust=76 ;fits for: 140-150cm height / 9-10 Years OldNote: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