How much does your head grow from birth to age 2?

From birth to age 2, a child's head grows significantly, increasing in size by about 50%. At birth, the average head circumference is around 35 centimeters (14 inches), and by age 2, it typically reaches about 47 centimeters (18.5 inches). This rapid growth reflects the development of the brain and skull, which undergoes substantial changes during this critical early period of life.