Baby Head Circumference Calculator

A head circumference percentile shows how your baby's head size compares to other babies of the same age and sex. For example, if your baby is in the 70th percentile for head circumference, their head is larger than 70% of babies their age. Percentiles between the 5th and 95th are generally considered within the normal range.

Head circumference is an important indicator of brain growth and development. Pediatricians measure it regularly during the first few years of life to ensure the brain is growing normally. Consistently tracking in the same percentile range over time is typically more important than the specific percentile itself.

Use a flexible measuring tape and wrap it around the widest part of your baby's head—typically just above the eyebrows and ears, around the back of the head where it curves out the most. The tape should be snug but not tight. For accuracy, take 2-3 measurements and use the largest one.

Head size varies greatly and is often genetic. A baby with a large head may simply have parents with large heads. What pediatricians watch for is consistency—a baby should roughly follow the same percentile curve over time. Sudden jumps or drops in percentile, or measurements far outside the normal range (below 3rd or above 97th), warrant discussion with your doctor.

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