How A Baby’s Head Circumference Indicates Normal Growth?

When you visit a pediatrician for your baby’s regular health checkup, the foremost thing they do is check your baby’s length and weight. While there is nothing unusual until the doctor turns to your baby head and measure your bub’s tiny crown with an inch tape. You wonder whether it is really necessary to take head measurements.

Your Baby’s Head Circumference

The head circumference is the measurement of the infant’s head around the largest area. It is measured keeping the tape above the eyebrows and ears to around the back of the head. The measurement is usually done in centimeters using a tape, which is either a flexible one or made out of paper.


Your baby’s head circumference at birth (at full-term) lies between 31.75 – 34.29 centimeters or 12.5-13.5 inches.

Does The Head Size Matter?

The head circumference is associated with the growth of the brain. When the baby’s brain is developing as it should, the circumference of the head will increase as per the standard measurements.


If the head circumference isn’t increasing, it is a sign of underdevelopment. Whereas if it is increasing rapidly, it could be an indication of hydrocephalus where there is a buildup of fluid in the brain. Though the chances are fairly rare, the measurements are necessary to completely rule them out.

The height and weight including the head circumference are recorded in percentile and is compared with the standards provided by the World Health Organization (WHO) for children in particular age groups. For infants between the ages of 1-2-year-olds, the Centers for Disease Control and Prevention (CDC) and the American Academy of Pediatrics (AAP) recommend the doctors to refer the charts provided by WHO for comparisons.


There is no percentile range for to compare the baby’s head circumference. Using the percentile score the doctors simply want to ascertain that the baby’s brain is growing normally and there are no abnormal patterns in the growth rate.

How Does A Baby’s Head Grow?

When your baby is born, their skull is made up of a number of different bones, which haven’t grown completely and fused together. These gaps are called soft spots or fontanelles. They help the baby during birth when their head passes through the birth canal. However,


Gradually, these pieces continue to grow and fuse together by the time they are 18 months of age. In the first 4 months, the head growth is rapid. Their head grows at the rate of half an inches every month. By their first birthday, the head circumference will be around 18 inches. The following year, the circumference reaches closer to the adult size. After the baby turns 2, the growth rate reduces significantly.

If you feel your baby’s head looks larger, you may be correct. A baby’s head is disproportionate to their body as compared to an adult. It also depends on whether you and/or your partner have a large or small head.


If the baby’s head circumference is smaller, the doctor will check for the other parameters—physical, mental and emotional development. In case the head size is abnormally larger, a CT scan is recommended to check the brain for signs of hydrocephalus.

The head circumference of a baby boy is found is to be greater than that of a baby girl. This is because males are larger and grow faster as compared to females.


Measuring the head circumference is important to keep a track of your baby’s growth. It can also help in early detection of conditions and disorders that can affect the child’s physical and intellectual development later in life making an early intervention beneficial in the diagnosis and treatment. Here is a head circumference chart by the WHO, provided separately for boys and girls.