Weight-for-Age Percentile Calculator (WHO, 5-10 Years)

How Weight-for-Age Percentiles Work (5-10 Years)

This calculator uses the WHO Growth Reference 2007 to assess weight-for-age for children aged 5 to 10 years (60 to 120 months). The WHO reference provides an international standard for monitoring weight during the school-age years.

The calculator applies the LMS method (Lambda-Mu-Sigma), a statistical technique that models the distribution of weight at each age using three parameters. Lambda (L) adjusts for skewness, Mu (M) represents the median, and Sigma (S) is the coefficient of variation.

Note: The WHO weight-for-age reference is only available up to age 10. After age 10, the WHO recommends using BMI-for-age instead of weight-for-age, because weight alone does not distinguish between lean mass and fat mass in older children and adolescents.

Understanding Weight Percentiles

A percentile indicates the percentage of children who weigh less than your child at the same age and sex. For example, the 60th percentile means 60% of same-age children weigh less.

• 3rd to 97th percentile is considered the normal range
• Below the 3rd percentile may indicate underweight
• Above the 97th percentile may indicate overweight
• The growth trend over time matters more than a single reading

Example Calculation

A 7-year-old boy (84 months) weighing 22.9 kg is approximately at the 50th percentile (Z-score near 0), since the WHO median weight for boys at 84 months is about 22.89 kg.

Frequently Asked Questions

Why does this calculator only go to age 10?

The WHO weight-for-age reference data only extends to 10 years (120 months). After age 10, the WHO recommends using BMI-for-age instead, because weight alone becomes less informative as children enter puberty and body composition changes significantly.

Should I use kg or pounds?

You can use either unit. The calculator converts pounds to kilograms automatically. For the most accurate result, use the weight recorded at your pediatrician’s office.

How is this different from the WHO 0-5 year calculator?

The WHO 0-5 year calculator uses the WHO Child Growth Standards (prescriptive, based on healthy breastfed children). This 5-10 year calculator uses the WHO Growth Reference 2007, which is a descriptive reference based on historical data reconstructed from multiple sources. Both use the LMS method for percentile calculation.

What should I do for children older than 10?

For children and adolescents aged 5-19 years, use our WHO BMI-for-Age calculator, which accounts for both weight and height. The CDC 2-20 year weight-for-age chart is also available if you prefer US-based reference data.