G-SIZE3

 Size Age Waist(in) Hip(in)
S 8-10 21-22 28-29.5
M 10-12 22-23 30-31.5
L 12-14 23-24 32-33.5
XL 14-16 24-25 34-35.5

The sizes are manually measured with error from 0.2 to 0.8 inches.