Child Growth Percentile Calculator
Exact weight, height, head and BMI percentiles from WHO and CDC growth charts.
Growth Percentile Calculator
Exact percentiles from the WHO Child Growth Standards (birth to 2 years) and CDC growth charts (2 to 20 years).
Measure length lying down under 2 years and standing height from 2 years.
Quick answer
A growth percentile shows how your child compares with others of the same age and sex: at the 40th percentile, 40 in 100 children measure less. Anywhere between the 3rd and 97th percentile is usually normal — doctors care most about whether a child keeps following their own curve.
How percentiles are calculated
We use the WHO Child Growth Standards from birth to 2 years and the CDC 2000 growth charts from 2 to 20 years — the combination the US CDC recommends. Each chart is described by three numbers at every age (L, M and S), which turn a measurement into an exact z-score and percentile.
Under 2 years, measure length lying down; from 2 years, measure standing height without shoes. Head circumference is measured around the widest part of the head, just above the eyebrows and ears. BMI-for-age is shown from 2 years.
In India, the Indian Academy of Pediatrics recommends WHO standards up to 5 years and the IAP 2015 charts for older children, so results after age 5 may differ slightly from what your paediatrician's chart shows.
Average (50th percentile) weight and length, birth to 2 years
WHO Child Growth Standards medians.
| Age | Boys weight | Boys length | Girls weight | Girls length |
|---|---|---|---|---|
| Birth | 3.3 kg | 49.9 cm | 3.2 kg | 49.1 cm |
| 3 months | 6.4 kg | 61.4 cm | 5.8 kg | 59.8 cm |
| 6 months | 7.9 kg | 67.6 cm | 7.3 kg | 65.7 cm |
| 9 months | 8.9 kg | 72.0 cm | 8.2 kg | 70.1 cm |
| 12 months | 9.6 kg | 75.7 cm | 8.9 kg | 74.0 cm |
| 18 months | 10.9 kg | 82.3 cm | 10.2 kg | 80.7 cm |
| 24 months | 12.2 kg | 87.8 cm | 11.5 kg | 86.4 cm |
Frequently asked questions
Is a low percentile bad?
Not on its own. A healthy child can grow steadily along the 10th percentile. Doctors look for measurements below the 3rd or above the 97th percentile, or a child crossing two main percentile lines over time.
Why WHO charts under 2 and CDC charts after?
WHO standards describe how healthy breastfed babies grow and are recommended for the first two years; CDC charts are used from 2 to 20 years.
My baby was born early. Which age should I use?
Use corrected age (age minus the weeks born early) until about 2 years old.
How often should I measure my child?
Follow your baby's check-up schedule. Single readings vary; trends over several visits matter most.
Talk to your doctor if
- A measurement is below the 3rd or above the 97th percentile
- Your child crosses two main percentile lines up or down
- Your baby is not back to birth weight by about 2 weeks old
- Weight is falling, or your child seems unwell, is feeding poorly or has very few wet nappies
In an emergency call 112 (India) or 911 (US). This tool gives general information, not medical advice.
Sources
Add this free calculator to your website
Copy this code into your page. It is free to use with the credit link.
<iframe src="https://parentingtipsandguide.com/embed/tools/growth-tracker" title="Child Growth Percentile Calculator" width="100%" height="720" style="border:0;max-width:720px" loading="lazy"></iframe> <p style="font-size:12px"><a href="https://parentingtipsandguide.com/tools/growth-tracker">Child Growth Percentile Calculator</a> by ParentingTipsAndGuide.com</p>