Size chart : 0-6 mois : 38 cm @ 42 cm (circumference) with cord and velcro 6-24 mois : 46 cm @ 50 cm (circumference) 2T - 5T : 50 cm @ 54 cm (circumference) 7-16 (Junior) : 54 cm @ 58 cm (circumference) *Sunscreen (spray or cream) can affect the condition of your cap. It is very important to remove the cap from the head when applying sun protection.