Children’s hat sizes
Hat sizes for babies and children are measured in either centimeters or inches. Here is a guide to the approximate size, based on the child’s age.
You can also measure the child’s hat size directly. Wrap a tape measure around the head just above the ears and at the center of the forehead. The tape should fit comfortably – not too tight. Round up to the nearest size. You can also use a piece of string, and then measure it with a normal ruler.
This chart is for boys and girls – look here for adult hat sizes.