Growth Curve Tool
Free · Private · Data-sourced from official standards

Baby & Child Growth Percentile Calculators

Enter your child's age and a measurement to see their percentile and Z-score, calculated entirely in your browser from official growth reference data — nothing is uploaded or stored. Pick a standard below: WHO's international reference, or Japan's official MHLW survey data.

🌐 WHO International Standard

World Health Organization Child Growth Standards (2006) — used as the reference in most countries worldwide.

Weight-for-age (0–5 years)

Percentile and Z-score for weight by age and sex.

Open calculator →

Height/length-for-age (0–5 years)

Percentile and Z-score for length or standing height by age and sex.

Open calculator →

Head circumference-for-age (0–5 years)

Percentile and Z-score for head circumference by age and sex.

Open calculator →

BMI-for-age (0–5 years)

Body mass index percentile, computed from weight and length/height.

Open calculator →

Source: WHO Child Growth Standards, official LMS reference tables.

🇯🇵 Japan Standard (MHLW)

Based on Japan's official growth survey by the Ministry of Health, Labour and Welfare (厚生労働省) — useful if your pediatrician in Japan references the Japanese percentile chart and you'd like to check it in English.

Weight-for-age

Percentile based on Japan's official 2023 national infant growth survey.

Open calculator →

Height-for-age

Percentile based on Japan's official 2023 national infant growth survey.

Open calculator →

Head circumference-for-age (0–3 years)

Percentile based on Japan's official survey — head circumference is only measured under age 3 as of the 2023 survey.

Open calculator →

Source: 厚生労働省 乳幼児身体発育調査報告書 (Japan's official national infant growth survey).