This is a beautiful, quality helmet. Unfortunately, I have to return the one I bought. In the description, it says, Extra Small: “Complies with the US CPSC Safety Standard for Bicycle Helmets for Persons Age 1 and Older” and Small: “Complies with the US CPSC Safety Standard for Bicycle Helmet for Persons Age 5 and Older”. As I didn’t see a size chart or other reference to size, I took this statement to mean the Small would fit a 6 year. (It only comes in extra-small and small.) My grandson is 6, but his head measures 21″ which is 53.34 cm. The small almost fits, but not quite, certainly wouldn’t be safe or protective. I had it delivered to my son’s house, but i have it now so I can return it, and it says on the box “Youth Small 49-53 cm / 19.25-20.75”. So measure your child’s head, just above the eyebrows. But I would definitely recommend if fitted properly. It’s a nice looking helmet. [...]