When in doubt, size up.

Women's
Bottom Sizes
Men's
Bottom Sizes
Height below 5'9" Height above 5'9"
00-0 26 XS S
2-4 28-30 S M
6-8 32-34 M L
10-12 36-38 L XL
14-16 40-42 XL 2XL
18 44 2XL 3XL
20-22 46-50 3XL 3XL