Size	Adult Head Circumference	Women's
One Size	21¾"-24" (55-61cm)	21¼"-23¼" (54-59cm)
Small/Medium	21¾"-22¾" (55-58cm)	21¼"-22" (54-56cm)
Large/Extra Large	22¾"-24" (58-61cm)	22"-23¼" (54-59cm)

Measurements refer to body size, not garment dimensions, unless otherwise noted.