Height Percentile Calculator for Children & Teens (CDC, 2–20 years)

Understanding the height percentile calculator for children and teens — concept and principle

This calculator compares a child's or teenager's height with the CDC 2000 growth charts for ages 2 to 20 and gives the percentile, z-score and the 5th, 50th and 95th percentile heights for that age and sex. Parents use it to read growth check results; health workers use it to spot children who are unusually short or tall or are drifting away from their curve.

Boy, 10 years, 140 cm: with the default inputs the result is 57th percentile (+1.2 cm above the median).

How it is calculated

z = ((height ÷ M)^L − 1) ÷ (L × S)

Percentile = share of the normal distribution below z

Height at a percentile = M × (1 + L × S × z)^(1/L)

L (skew), M (median) and S (spread) come from the CDC tables for each sex and half-month of age.
Age is taken at the middle of the month (years × 12 + months + 0.5) and values between table ages are interpolated.

The principle

Heights at a given age are not perfectly symmetric. The LMS method of Cole fixes this with a power transformation (the L value) that makes the distribution normal, after which a standard z-score can be used. M is the median and S the coefficient of variation. The percentile tells you what share of the reference children of the same age and sex were shorter.

Worked example

Default inputs: boy, 10 years 0 months, height 140 cm.

Age in months = 120 + 0 + 0.5 = 120.5; CDC values: L = 0.5056, M = 138.82 cm, S = 0.04761.
(140 ÷ 138.82)^0.5056 = 1.00430; z = 0.00430 ÷ (0.5056 × 0.04761) = 0.18.
Percentile = 57.
Median 138.8 cm; difference = 140 − 138.8 = 1.2 cm.
5th percentile 128.2 cm, 95th 149.9 cm.

How to read the result

Where does your result fall?

Anywhere between the 5th and 95th percentile is common. Children usually follow their own curve, so crossing two or more major percentile lines, or a height far from what parents' heights suggest, deserves a check. Puberty timing shifts teenage percentiles temporarily.

Common mistakes

Measuring with shoes on or with the head tilted.
Using this chart for children under 2; WHO standards are used then.
Over-reading one measurement instead of the trend.

Keep in mind: This is not a diagnosis. Concerns about growth should be discussed with your child's doctor.

Frequently asked questions

What height percentile is normal?

Most children are between the 5th and 95th; the percentile itself matters less than steady growth.

Why does my child's percentile change?

Small changes are measurement noise; big changes may reflect early or late puberty or a health issue.

Are CDC charts used outside the US?

Many countries have national charts. Results can differ slightly from CDC values.

Sources: Kuczmarski RJ et al., "2000 CDC Growth Charts for the United States: Methods and Development", Vital Health Stat 11(246), 2002 · Cole TJ, Green PJ, "Smoothing reference centile curves: the LMS method and penalized likelihood", Stat Med 1992;11:1305–1319

Checked 9 Nov 2026. CDC 2000 growth charts, stature-for-age LMS parameters, 2–20 years (Kuczmarski RJ et al., “2000 CDC Growth Charts for the United States: Methods and Development”, Vital Health Stat 11(246), 2002). LMS values as distributed in the RCPCH rcpchgrowth package.

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