Normal head circumference of a 4-year-old child

Patient's question:

Age
Detailed medical condition and consultation purpose: Doctor: Hello!
　My child is 4 years old, and his head circumference is 50CM (1 foot 5 inches). Is this normal? What is the normal head circumference for a 4-year-old child?

Doctor's answer:

1. Male child, 4 years old: Average weight is 16.70 kilograms, average height is 102.9 centimeters, average head circumference is 49.8 centimeters, average chest circumference is 52.3 centimeters.