Newborn - 12" extends to 13"
Infant - 14" extends to 15.5"
Child - 15.5" extends to 18"
Teen/Adult - 18"
Custom- you can leave me the exact measurement you need or the age of the person you are buying for in the note section of checkout.
Please measure your child's head before selecting a size if you are unsure. If you still have questions about sizing, please send me a email me firstname.lastname@example.org