It is more accurate to compare with height:
(Unit: CM)
110=3T-4T: Length=61, Waist=44, Hips=72; Suitable for: 100-110 cm height / 3-4 years

120 = 5T: Length = 66 cm, Waist = 44 cm, Hips = 76 cm; Suitable for: 110-120 cm height / 5 years old

130=6T: Length=70, Waist=46, Hips=78; Suitable for: 120-130 cm height / 6 years old

140=7T: Length=74 cm, Waist=48 cm, Hips=80 cm; Suitable for: 130-140 cm height / 7 years old

150=8T-9T: Length=79 cm, Waist=48 cm, Hips=82 cm; Suitable for: 140-150 cm tall / 8-9 years old

160=10T-11T: Length=84 cm, Waist=50 cm, Hips=86 cm; Suitable for: 150-155 cm height / 10-11 years old

170=12T-13T: Length = 89 cm, Waist = 52 cm, Hips = 90 cm; Suitable for: 155-160 cm height / 12-13 years old
Noticed :
1. There is a 2-3% difference according to manual measurement. (1 inch = 2.54 cm)
2. All measurements are in cm, please note 1 cm = 0.3937 channels, 1 inch = 2.540 cm.
3. Please check the measurements carefully and order the correct size; do not rely solely on the "age guidelines." These are for reference only.