Fit and sizes:Sizing is based on head circumference:XXS infant (15-16” / 38-40.5 cm)XS baby (16-17” / 40.5-43 cm)S toddler (17-18” / 43-46 cm)M child (19-21” / 48-53 cm)L teen/small adult (21-22” / 53-56 cm)XL large adult (22-23” / 56-58.5 cm)XXL extra large adult (23-24” / 58.5-61 cm)