Baby Head Circumference Calculator

Measuring a baby's head circumference is an important part of monitoring growth and development. This calculator helps you determine the head circumference in centimeters or inches based on the measurement you take.

What is head circumference?

Head circumference is the measurement around the largest part of a baby's head, typically just above the ears. It's one of the most important growth indicators for newborns and infants. Monitoring head circumference helps healthcare providers track whether a baby is growing normally or if there might be any developmental concerns.

Head circumference is different from head length, which measures from the top of the head to the base of the skull.

How to measure baby's head circumference

Measuring a baby's head circumference requires a soft, non-stretchy measuring tape. Here's how to do it properly:

Choose a soft, flexible measuring tape that's at least 30 inches long.
Place the tape around the baby's head just above the ears, following the natural curve of the head.
Make sure the tape is snug but not tight - it should fit comfortably without pulling.
Record the measurement in centimeters or inches.

Always measure head circumference when the baby is awake and alert, not during a feeding or when the baby is asleep.

Normal head circumference measurements

Head circumference measurements vary by age. Here are some general guidelines:

Age	Head Circumference (cm)	Head Circumference (inches)
Newborn (0-2 weeks)	33-36	13-14
1 month	36-38	14-15
3 months	40-42	16-17
6 months	43-45	17-18
9 months	45-47	18-19
12 months	46-48	18-19

These are approximate ranges. Always consult with a healthcare provider for personalized advice about your baby's growth.

When to see a doctor

While head circumference measurements can help monitor growth, they should not be used in isolation. Here are some situations when you should contact your pediatrician:

If your baby's head circumference is significantly larger or smaller than the expected range for their age
If you notice any signs of developmental delays or concerns
If your baby has a history of genetic conditions that affect growth
If you're concerned about your baby's overall growth and development

Regular check-ups with your pediatrician are essential for monitoring your baby's growth and development.

FAQ

How often should I measure my baby's head circumference?

Newborns should have their head circumference measured at birth and then again at 1 month, 3 months, and 6 months. After that, measurements are typically done during regular well-child visits.

Can I use a ruler to measure my baby's head circumference?

No, a measuring tape is the most accurate tool for measuring head circumference. Rulers can't properly measure the curve of the head.

What if my baby's head circumference is outside the normal range?

If your baby's head circumference is significantly larger or smaller than the expected range, contact your pediatrician for evaluation. They can determine if there are any concerns about your baby's growth and development.

Is head circumference the same as head size?

Head circumference refers specifically to the measurement around the largest part of the head, while head size can refer to overall dimensions including length and width.