Height-for-Age Percentile Calculator (WHO, 5-19 Years)

How Height-for-Age Percentiles Work (5-19 Years)

This calculator uses the WHO Growth Reference 2007 to assess height-for-age for children and adolescents aged 5 to 19 years (60 to 228 months). The WHO reference was developed from data collected across multiple countries and provides an international standard for monitoring growth during childhood and adolescence.

The calculator applies the LMS method (Lambda-Mu-Sigma), a statistical technique that models the distribution of height at each age using three parameters. Lambda (L) controls skewness, Mu (M) represents the median, and Sigma (S) is the coefficient of variation. Together, these parameters allow the calculator to determine exactly where a child falls compared to the reference population.

Understanding Height Percentiles

A percentile indicates the percentage of children who are shorter than your child at the same age and sex. For example, a child at the 75th percentile is taller than 75% of peers.

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

Example Calculation

An 8-year-old boy (96 months) with a height of 127.3 cm would be approximately at the 50th percentile (Z-score near 0), since the WHO median height for boys at 96 months is about 127.29 cm.

Frequently Asked Questions

What age range does this calculator cover?

This calculator uses the WHO Growth Reference 2007 for children and adolescents aged 5 to 19 years (60 to 228 months). For younger children, use our WHO 0-5 year stature-for-age calculator.

Should I measure height in cm or inches?

You can use centimeters, inches, or feet and inches. The calculator converts automatically. For the most accurate result, use a stadiometer reading from your doctor’s office.

How is this different from the CDC growth chart?

The WHO Growth Reference 2007 is an international standard based on data from multiple countries, while the CDC charts are based on US data from the 1960s-1990s. The WHO reference describes how children should grow under healthy conditions, while the CDC charts describe how US children actually grew.

When should I be concerned about my child’s height?

A single height measurement below the 3rd or above the 97th percentile, or a significant change in growth trajectory, may warrant discussion with your pediatrician. Growth patterns over time are more informative than any single measurement.