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Newborn head circumference

At birth, most full-term babies measure 32 to 37 cm around the head. Here is what is normal and how the measurement is used.

Head circumference percentile calculator

Sex

Enter the head circumference to see the percentile.

Data: WHO Child Growth Standards (0 to 24 months) and CDC growth charts (24 to 36 months).

Average head circumference at birth

Ranges are the WHO 2.3rd to 97.7th percentiles for full-term babies. Premature babies are assessed on separate charts that use their corrected age.

  • Boys: median 34.5 cm (13.6 in), normal range about 31.9 to 37.0 cm.
  • Girls: median 33.9 cm (13.3 in), normal range about 31.5 to 36.2 cm.

How a newborn’s head is measured

A nurse or midwife wraps a paper or plastic tape around the widest part of the head, just above the eyebrows and ears. Moulding during birth can change the shape of the head for a few days, so the measurement is often repeated after a day or two.

How fast a newborn’s head grows

A newborn’s head grows about 2 cm a month for the first three months. By the first birthday it is usually 11 to 12 cm larger than at birth.

How to measure your head

  1. 1 Use a soft tape measure, or a string and a ruler.
  2. 2 Wrap it around your head where the hat will sit: about 1 cm (⅜ in) above your ears and across the middle of your forehead.
  3. 3 Keep the tape level and snug, not tight. Do not pull it in.
  4. 4 Read the number where the tape overlaps. Measure two or three times and use the largest value.
  5. 5 Type the number into the calculator, or find it in the chart.
How to measure

Frequently asked questions

What is a normal head circumference for a newborn?

About 32 to 37 cm (12.6 to 14.6 in) for a full-term baby. The WHO median is 34.5 cm for boys and 33.9 cm for girls.

How big is a baby’s head for a normal delivery?

At term the head is about 34 cm around, and its widest side-to-side width, the biparietal diameter, is usually about 9 to 10 cm.

Is a 36 cm head big for a newborn?

For a boy, 36 cm is close to the 90th percentile; for a girl, it is above the 95th. Both are usually within the normal range, and doctors look at growth over the following weeks.

Why is my newborn’s head misshapen?

Moulding during birth is common and usually settles within days. Ask your midwife or doctor if the shape worries you or does not improve.

Related charts

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