0-3 months old.
Newborn sizes are often identified by the age range in months (0–3) or just “newborn.”
3–12 months old.
Infant sizes are often identified by the age range in months (3–12).
1–5 years old.
Toddler sizes are often identified by the age range in months (12–24) or years (1–5).
5–13 years old.
Children's sizes are often identified by the age range in years (5-13).
7–18 years old (varies in every region globally).
Youth's sizes are often identified by the age range in years (7-18).
Typically teens or older (13 years old or more).
All sizes within this age group have been manufactured to fit an adult or teen.
