Girls Sizes:

S-7 = 22"-23" Waist
M-8/10 = 23.5"-24.5" Waist
L-12/14 = 25"-26" Waist
XL-16 = 26.5"-27.5" Waist

Juniors Sizes:

XS-0/1 = 22"-23.5" Waist
S-3/5 = 23.5"-25" Waist
M-7/9 = 25.5"-27.5" Waist
L-11/13 = 28"-30" Waist
XL-15 = 30.5"-32.5" Waist