Sizing:
Newborn: fits up to 4 weeks.
0-3 months: fits up to 15-inch head.
3-6 months: fits up to 17-inch head.
6-12 months: fits up to 19-inch head.
12-18 months: fits up to 20-inch head.
18 months-2 years: fits up to 21-inch head.
3-5 years: fits up to 22-inch head.
**To measure, wrap a measuring tape around the head, just above the ears and eyebrows.**