Head Circumference Percentile Calculator

Calculate head circumference percentiles for children using WHO growth standards

Calculate Head Circumference Percentile

Growth patterns differ slightly between boys and girls

Valid range: 0-60 months (5 years)

Measure around the widest part of the head, above eyebrows and ears

Head Circumference Assessment Results

Enter your child's information to calculate head circumference percentile

Valid age range: 0-60 months (birth to 5 years)

How to Measure Head Circumference

Measurement Steps

  1. Use a non-stretchable measuring tape (or string)
  2. Position tape above the eyebrows (one finger width above)
  3. Wrap around the widest part of the head, above the ears
  4. Include the most prominent part of the back of the head
  5. Ensure tape is snug but not tight
  6. Take the largest of three measurements

Tips for Accurate Measurement

  • • Measure when baby is calm and still
  • • Avoid measuring over hair accessories or when hair is wet
  • • Use the same measuring technique each time
  • • Record measurements to track growth over time

Percentile Interpretation

Microcephaly: <3rd percentile
Below Normal: 3rd-10th percentile
Normal Range: 10th-90th percentile
Above Normal: 90th-97th percentile
Macrocephaly: >97th percentile

Average Head Sizes

Birth:34-35 cm
1 month:36-37 cm
3 months:39-40 cm
6 months:42-43 cm
12 months:45-46 cm
24 months:47-48 cm

These are approximate averages (50th percentile)

Medical Disclaimer: This calculator provides estimates for educational purposes only. Head circumference measurements should always be interpreted by qualified healthcare professionals in the context of overall growth and development.

Understanding Head Circumference Percentiles

Why Monitor Head Circumference?

Head circumference reflects brain growth and development. It's one of the most important measurements in pediatric healthcare, helping doctors assess neurological development and detect potential issues early.

Clinical Significance

  • Microcephaly (<3rd percentile): May indicate genetic disorders, infections, or brain malformations
  • Normal Range (10th-90th percentile): Indicates typical brain growth
  • Macrocephaly (>97th percentile): May indicate hydrocephalus or other conditions

Growth Monitoring

Normal Growth Pattern

Child follows same percentile channel over time

Concerning Pattern

Crossing two or more percentile lines rapidly

Measurement Frequency

Regular pediatric visits track growth over time

WHO Growth Standards

This calculator uses World Health Organization (WHO) growth standards, developed from data collected in the WHO Multicentre Growth Reference Study. These standards represent optimal growth for children up to 5 years of age and are used globally by healthcare professionals.