Is a low percentile (e.g., 10th) a sign that something is wrong?

No, not necessarily. Percentile simply shows how your child compares to a reference population — a child at the 10th percentile for weight is not unhealthy; it means 10% of children of the same age and sex weigh the same or less. A wide range from approximately the 3rd to the 97th percentile is considered typical. What matters most is whether your child's growth curve is following a consistent trend over time. If you have concerns about your child's growth pattern, please consult a qualified paediatrician.

What is the difference between WHO and CDC growth standards?

The WHO Child Growth Standards (2006) describe how children should grow under optimal conditions (exclusive breastfeeding, non-smoking environment, good healthcare). The data was collected from six countries across diverse regions. The CDC Growth Charts (2000) are based on a US national reference population that includes both breastfed and formula-fed children. WHO standards are generally recommended for children under 2 years globally, while CDC charts are commonly used in US clinical settings for children 2 years and older.

How accurate is this calculator?

This calculator uses the standard LMS (Lambda-Mu-Sigma) method with published WHO and CDC reference parameters, which is the same statistical method used in clinical growth chart software. Percentile values are interpolated linearly between published data points at monthly or 3-month intervals. The results are sufficiently accurate for reference purposes, but minor differences from other tools may occur due to interpolation. This tool is not a substitute for clinical assessment by a healthcare professional.

Baby Growth Percentile Calculator

Child's Information

Sex

Age (months)

Weight (kg)

Height / Length (cm)

Growth Reference

WHO is recommended for children 0–2 years worldwide; CDC is commonly used for US children 2 years and older.

Save age, weight, and height in this browser for next visit. (Optional. Data stays on your device — never sent to any server.)

About This Tool

Calculate your baby's weight and height/length percentiles (0–60 months) using WHO or CDC growth standards. Enter sex, age, weight, and height to instantly see where your child falls on the growth chart. For informational reference only — always consult a paediatrician for clinical assessment.

This calculator uses the standard LMS (Lambda-Mu-Sigma) method to compare a child's measurements against a reference population. WHO standards (2006) are based on children raised under optimal conditions in six countries; CDC charts (2000) are based on a US national reference population.

How To Use

Select the child's sex — growth standards are sex-specific; an accurate sex selection is required.
Enter age in completed months — within 0–60 months (e.g. 12 for a one-year-old).
Enter weight in kilograms — use a recent measurement from a calibrated scale.
Enter height or length in centimetres — use recumbent length (lying) for children under 24 months, standing height for 24 months and older.
Select the growth reference (WHO or CDC) — WHO is recommended for children under 2 worldwide; CDC is common in US clinical settings.
Click Calculate Percentile — weight and height percentiles are shown with gauge bars.

Example

Example: 6-month-old boy — 7.5 kg, 68 cm (WHO reference)

WHO 6-month boys weight median: 7.93 kg → 7.5 kg is slightly below median

→ Weight approximately 35–40th percentile (35–40% of peers weigh the same or less)

A percentile of 35–40 falls within the typical range (approximately 3rd–97th percentile). Do not use this result alone to judge your child's health — growth trends and overall wellbeing matter more than a single measurement. Consult a paediatrician for clinical evaluation.

Frequently Asked Questions

Is a low percentile (e.g., 10th) a sign that something is wrong?: No, not necessarily. Percentile simply shows how your child compares to a reference population — a child at the 10th percentile for weight is not unhealthy; it means 10% of children of the same age and sex weigh the same or less. A wide range from approximately the 3rd to the 97th percentile is considered typical. What matters most is whether your child's growth curve is following a consistent trend over time. If you have concerns about your child's growth pattern, please consult a qualified paediatrician.
What is the difference between WHO and CDC growth standards?: The WHO Child Growth Standards (2006) describe how children should grow under optimal conditions (exclusive breastfeeding, non-smoking environment, good healthcare). The data was collected from six countries across diverse regions. The CDC Growth Charts (2000) are based on a US national reference population that includes both breastfed and formula-fed children. WHO standards are generally recommended for children under 2 years globally, while CDC charts are commonly used in US clinical settings for children 2 years and older.
How accurate is this calculator?: This calculator uses the standard LMS (Lambda-Mu-Sigma) method with published WHO and CDC reference parameters, which is the same statistical method used in clinical growth chart software. Percentile values are interpolated linearly between published data points at monthly or 3-month intervals. The results are sufficiently accurate for reference purposes, but minor differences from other tools may occur due to interpolation. This tool is not a substitute for clinical assessment by a healthcare professional.

This calculator is for informational purposes only and does not constitute medical advice. Results are estimates based on general formulas. Always consult a qualified healthcare professional for health-related decisions.

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