Child Growth Percentile Calculator
Calculate child growth percentiles for height, weight, and BMI using WHO and CDC growth charts by age and gender
Enter weight in kilograms
Enter height in centimeters. For children under 2, use recumbent length.
Weight-for-Age
Height-for-Age
BMI-for-Age
Weight-for-Age Percentile
Height-for-Age Percentile
BMI-for-Age Percentile
Understanding Child Growth Percentiles
Growth percentiles indicate how a child's measurements compare to other children of the same age and sex. A child at the 50th percentile is right at the median — half of children their age weigh more, and half weigh less. Being at a higher or lower percentile does not necessarily mean a child is healthier or less healthy; what matters most is consistent growth along a child's own growth curve over time.
Pediatricians track these percentiles at regular well-child visits to monitor growth patterns and identify potential nutritional or developmental concerns early. A sudden shift across percentile lines (crossing two or more major percentile lines) is typically more concerning than a child's absolute position on the chart.
The LMS Method
This calculator uses the LMS method (Lambda-Mu-Sigma), the same statistical approach used by the CDC and WHO to construct growth charts. The three parameters at each age describe the distribution of measurements:
- L (Lambda) — Box-Cox power transformation to normalize the data
- M (Mu) — Median value at that age (the 50th percentile)
- S (Sigma) — Generalized coefficient of variation (spread)
Z-score = [( X / M )L − 1] / ( L × S )
where X is the child's measurement, and L, M, S are age- and sex-specific parameters
WHO vs. CDC Growth Charts
WHO Growth Standards (0–2 years)
- • Based on the Multicentre Growth Reference Study (MGRS)
- • Describes how children should grow under optimal conditions
- • Data collected from 6 countries (Brazil, Ghana, India, Norway, Oman, USA)
- • Exclusively or predominantly breastfed infants
- • Recommended by AAP for children under 2 years
CDC Growth Charts (2–20 years)
- • Based on US national survey data (NHANES & others)
- • Describes how children did grow in the US population
- • Published in 2000, revised with updated LMS data
- • Includes BMI-for-age charts for ages 2–20
- • Standard reference for children aged 2 and older in the US
The American Academy of Pediatrics (AAP) recommends using WHO growth standards for children under 2, and CDC growth charts for children aged 2–20. This calculator uses CDC-based reference data for all ages.
Interpreting Percentile Ranges
Weight-for-Age & Height-for-Age
| Percentile Range | Classification | Clinical Significance |
|---|---|---|
| Below 3rd | Very Low | May indicate undernutrition or growth disorder; further evaluation recommended |
| 3rd – 10th | Below Average | Monitor closely; may be normal for some children |
| 10th – 85th | Normal / Healthy | Typical growth range; most children fall here |
| 85th – 95th | Above Average | Monitor trends; may be normal for some children |
| Above 95th | Very High | May warrant further evaluation for overweight or growth abnormality |
BMI-for-Age (Children 2–20 Years)
| Percentile Range | Weight Status Category |
|---|---|
| Below 5th | Underweight |
| 5th – 85th | Healthy Weight |
| 85th – 95th | Overweight |
| Above 95th | Obese |
Source: CDC BMI-for-age weight status categories for children and teens aged 2–20 years.
Typical Growth Milestones
- Birth to 12 months: Infants typically triple their birth weight and grow about 25 cm (10 in) in length during the first year
- 1–3 years: Growth velocity slows; children gain about 2 kg (4.5 lb) and 8–10 cm (3–4 in) per year
- 3–5 years: Steady growth of about 2 kg (4.5 lb) and 6–8 cm (2.5–3 in) per year
- 6–10 years: Gradual, consistent growth of about 3 kg (6.5 lb) and 5–6 cm (2–2.5 in) per year
- Puberty (varies): A growth spurt with rapid gains in height (girls: ~8–10 cm/yr, boys: ~10–12 cm/yr at peak velocity) and weight
- Post-puberty: Growth velocity decreases; most girls reach adult height by 14–16 years, boys by 16–18 years
References
The growth reference data and clinical guidelines used in this calculator are based on the following sources:
- CDC — Growth Charts
- CDC — Percentile Data Files with LMS Values
- WHO — Child Growth Standards
- AAP Clinical Report — Use of World Health Organization and CDC Growth Charts for Children 0–59 Months
- Kuczmarski RJ, et al. “2000 CDC Growth Charts for the United States: Methods and Development.” Vital Health Stat, 2002
- WHO Multicentre Growth Reference Study Group. “WHO Child Growth Standards based on length/height, weight and age.” Acta Paediatrica, 2006
Note: This calculator provides estimates based on CDC growth reference data and is intended for educational and informational purposes only. It is not a substitute for professional medical advice. Growth patterns vary among individual children, and many factors — including genetics, nutrition, health conditions, and ethnicity — influence growth. Always consult your child's pediatrician for personalized growth assessment and any concerns about your child's development.
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