How to Measure and Interpret Your Baby’s Cephalic Index


As a parent, it’s natural to have concerns about your baby’s development, including their head shape. The cephalic index is a measurement that can help you understand your baby’s head shape and size. Here’s how you can measure and interpret your baby’s cephalic index:

Measuring the Cephalic Index

To measure your baby’s cephalic index, you will need a flexible measuring tape. Follow these steps:

  1. Place the measuring tape around your baby’s head, just above their eyebrows and ears.

  2. Take the measurement in centimeters. Make sure the tape is snug but not too tight.

  3. Record the measurement.

Interpreting the Cephalic Index

The cephalic index is calculated using the following formula:

Cephalic Index = (Head Width / Head Length) x 100

Once you have calculated the cephalic index, the results can be interpreted as follows:

  • A cephalic index of less than 75 indicates a dolichocephalic head shape, which is long and narrow.

  • A cephalic index between 75 and 85 indicates a mesocephalic head shape, which is considered average.

  • A cephalic index of greater than 85 indicates a brachycephalic head shape, which is short and wide.

What the Cephalic Index Can Tell You

Measuring your baby’s cephalic index can provide insight into their head shape and size. While variations in head shape are common and often resolve on their own as the baby grows, certain conditions such as craniosynostosis may lead to abnormal head shapes. If you have any concerns about your baby’s head shape or the cephalic index measurement, it’s important to consult with your pediatrician for further evaluation and guidance.


Monitoring your baby’s cephalic index can be a useful tool in understanding their head shape and size. By measuring and interpreting the cephalic index, you can gain valuable insight into your baby’s development. Remember, every baby is unique, and variations in head shape are normal. If you have any concerns, don’t hesitate to reach out to your pediatrician for guidance and support.


1. Is it normal for my baby’s head shape to change over time?

Yes, it is normal for a baby’s head shape to change as they grow. The soft spots on their skull allow for some flexibility, and most variations in head shape will resolve on their own.

2. When should I be concerned about my baby’s head shape?

If you notice any significant changes in your baby’s head shape or if the cephalic index measurement falls outside the typical range, it’s best to consult with your pediatrician for further evaluation.

3. Can the cephalic index measurement diagnose craniosynostosis?

While the cephalic index measurement can provide insight into head shape, a diagnosis of craniosynostosis requires a thorough evaluation by a medical professional, often including imaging tests.

4. How often should I measure my baby’s cephalic index?

It’s not necessary to measure your baby’s cephalic index regularly unless you have specific concerns about their head shape. Consult with your pediatrician if you have any questions or notice any changes.