Measure your waist around the slimmest part of your waist and your hip around the widest part of your hip. Measurements are given in inches. Kids who wear size 14 / XL will fit into an adult size XS if youth XL is unavailable. Similarly, youth 16 / XXL fits like an adult size Small.

Size Hip (in) Waist (in) Youth Size
XS 24.5-26 20.5-22 5/6
S 26-28 22-23.5 7
M 28-30 23.5-25 8/10
L 30-32 25-26 12
XL 32-34 26-27.5 14
2X 34-36 27.5-29 16