Quickly check your baby’s weight, height and head-circumference percentiles using WHO standards (0–5 years). Enter DOB to auto-calc age, choose metric or imperial units, and generate a printable growth report.
Baby Growth Percentile Calculator (WHO 0–5 Years)
Analyze your baby’s growth percentile based on WHO standards for weight, height, and head circumference.
Use this calculator to estimate your baby’s weight, height (length) and head-circumference percentiles compared to WHO growth standards for ages 0–5 years. The tool supports metric and imperial units, auto-calculates age from date of birth, and provides interactive charts and a PDF report.
What is this calculator?
This calculator estimates where your child falls relative to international growth standards by returning percentile values for weight, height (length) and head circumference. A percentile shows the percentage of children in the WHO reference population who have a lower measurement — for example, the 60th percentile means the child is larger than 60% of children of the same age and sex.
Why is this needed?
Tracking growth percentiles helps parents and clinicians detect growth problems early — including undernutrition, rapid weight gain, or disproportionate head growth. Percentiles are used to monitor growth trends over time, not just single values.
Some important facts
- WHO growth standards are the global reference for healthy child growth and are commonly used for ages 0–5 years.
- Percentiles are age- and sex-specific — always enter the correct age (in months) and gender.
- Single measurements matter less than trends. Sudden drops or rises in percentile merit professional review.
Real-life examples
Example 1 — Normal growth: A 12-month old girl with weight 9.5 kg and length 74 cm might be around the 50–75th percentile for weight and height — a typical, healthy range.
Example 2 — Low percentile: A 6-month old boy weighing 5.5 kg may fall below the 10th percentile for weight, which could indicate slower weight gain and should prompt a check with a pediatrician (feeding history, illness, or measurement accuracy are reviewed).
How to use the calculator
- Enter your baby’s date of birth — age in months will be calculated automatically.
- Select the baby’s gender (boy/girl).
- Choose units (Metric: kg/cm or Imperial: lb/in) and enter current weight, height (length) and head circumference.
- Click Calculate to view individual percentiles, growth categories, and trend charts. Use PDF export to save or share the report.
Why to use percentiles (benefits)
Percentiles provide a simple, comparable metric across ages and sexes. Benefits include early detection of nutritional problems, monitoring recovery after illness, and helping pediatricians tailor advice on feeding and care.
General information & history
The World Health Organization (WHO) released international growth standards based on healthy, breastfed children from multiple countries to provide a global benchmark. These standards replaced many older references and are used widely by health services for ages 0–5 years.
All formulas (used by this calculator)
Note: This calculator uses WHO reference mean values for given age/sex brackets and reports an approximate percentile using a ratio method. More precise percentile estimation in clinical practice uses LMS (Lambda-Mu-Sigma) parameters and z-scores; this tool provides an easy-to-understand approximation for parents.
Approximate percentile (simple method used here):
Percentile ≈ (Measured Value ÷ WHO Mean for the same age & sex) × 100
Interpreting the result:
- Percentile < 85 — Below average (possible undergrowth; check trend and consult pediatrician if persistent)
- Percentile 85–115 — Normal growth
- Percentile > 115 — Above average (possible rapid growth/overweight; consult pediatrician if unexpected)
Notes on units and conversions:
- 1 lb = 0.453592 kg
- 1 inch = 2.54 cm
Some tips for accurate measurements
- Weigh infants without heavy clothes and use the same scale if tracking over time.
- Measure length/height with a rigid measuring surface (infants laid flat for length).
- Measure head circumference at the largest part (above the eyebrows and around the back of the head).
- Record measurements regularly (same time of day when possible) to observe trends.
Frequently Asked Questions (FAQ)
How accurate is this baby growth calculator?
It gives a close, parent-friendly estimate using WHO mean values and simple math. For clinical accuracy (z-scores and precise percentiles), a pediatrician or growth-chart tool using LMS parameters should be used.
What percentile is considered healthy?
Most pediatricians consider growth between the 15th and 85th percentiles to be within a broadly healthy range. However, individual circumstances, parental size, and growth trends matter more than a single percentile.
My baby’s percentile changed quickly — should I worry?
Rapid, sustained drops or rises in percentile over a few visits should be discussed with a pediatrician. Temporary changes can follow illness or measurement differences.
Does this calculator work for premature babies?
For preterm infants you should use corrected (adjusted) age when comparing to WHO standards. Corrected age = chronological age − weeks born early. Consult your pediatrician for guidance.
Can I use this tool instead of medical advice?
No. This tool is for education and quick reference only. It does not replace regular pediatric care, growth assessments, or professional medical advice.
Disclaimer
The content on this page and the calculator are for informational purposes only and are not a substitute for professional medical evaluation, diagnosis, or treatment. Always seek the advice of a pediatrician or qualified healthcare provider with any questions regarding your child’s growth and health.