Head sizes (circumference):
Newborn | 13-14" | |
3-6 months | 14-17" | |
Toddler | 18-20" | |
3-10 years old | 19-20.5" | |
Teens | 20.5-22" | |
Woman | 21-23.5" | |
Man | 22-24.5" |
I always make hats a little smaller than the circumference of the head, because they are stretchy.