There is no size indication, but my child wore it from about 2 to 4 years old. I think my child's head is on the larger side. My child usually dislikes wearing hats, but this one was soft and they wore it without complaint. Since it can be adjusted with the strings, I think it can be worn from about 2 to 6 years old. We didn't go out much due to COVID, so it was only worn a few times. It is in very clean condition.