Head Circumference Percentile Calculator
Estimate your infant or toddler’s head circumference percentile for their age and sex, based on typical WHO growth reference values.
Why head circumference is tracked
Head circumference is measured regularly in infancy and early childhood because it reflects brain growth. Comparing a measurement to a percentile chart for age and sex helps show whether growth is following a typical, steady pattern over time.
How this calculator works
Enter your child’s sex, age in months (up to 36 months), and measured head circumference. The calculator compares that value to a typical median head circumference reference for that age and sex (based on widely published WHO growth standards) and estimates a percentile using a standard statistical approximation.
Note: This is a general estimate for educational purposes, not an official growth chart plot. A single measurement matters less than the overall trend, so always discuss head circumference tracking with your pediatrician.