Find a child's height percentile for age using the official CDC 2000 stature-for-age LMS data, ages 2 to 20, with the z-score and the median for that age.
| Input | Result |
|---|---|
| 10-year-old boy, 140 cm | about the 52nd percentile |
| 10-year-old girl, 140 cm | about the 57th percentile |
| 5-year-old boy, 110 cm | about the 54th percentile |
| 15-year-old boy, 170 cm | about the 43rd percentile |
A growth percentile compares your child with a reference population of the same age and sex — not with "normal". The 50th percentile is the median, not a target. A healthy child can sit steadily at the 10th percentile for years, and that is a different situation from a child who drops from the 60th to the 10th in six months.
This is why pediatric practice looks at the curve, not the number. A single measurement tells you where a child is; two or three measurements over time tell you how they are growing, which is the thing that actually carries information. Very few children track a constant percentile — most move up or down one band between visits and that is normal.
| Percentile | What it means |
|---|---|
| Below 3rd | Common referral threshold for short stature. Investigated, not automatically treated. |
| 3rd to 97th | The range standard growth charts plot. Anywhere in here can be completely normal. |
| Above 97th | Outside the printed chart. Usually constitutional tall stature, especially if parents are tall. |
Growth charts matter more as a series than as a point. Pediatric endocrinology guidance treats a child who crosses downward through two or more percentile lines as the more meaningful signal, even if the final percentile is still within range.
These are the reference values themselves, not estimates: the M column of the CDC LMS file is the 50th percentile, so this table is the published median for each age and sex. Whole-year ages are interpolated between the published monthly rows.
| Age | Boys | Girls |
|---|---|---|
| 2 years | 86.5 cm | 85.0 cm |
| 3 years | 95.0 cm | 93.9 cm |
| 4 years | 102.2 cm | 100.8 cm |
| 5 years | 108.9 cm | 107.7 cm |
| 6 years | 115.4 cm | 114.7 cm |
| 7 years | 121.8 cm | 121.5 cm |
| 8 years | 127.9 cm | 127.6 cm |
| 9 years | 133.5 cm | 132.9 cm |
| 10 years | 138.6 cm | 138.0 cm |
| 11 years | 143.5 cm | 144.0 cm |
| 12 years | 149.1 cm | 151.2 cm |
| 13 years | 156.1 cm | 157.2 cm |
| 14 years | 163.8 cm | 160.4 cm |
| 15 years | 169.9 cm | 161.9 cm |
| 16 years | 173.5 cm | 162.5 cm |
| 17 years | 175.3 cm | 162.9 cm |
| 18 years | 176.2 cm | 163.1 cm |
| 19 years | 176.6 cm | 163.3 cm |
| 20 years | 176.8 cm | 163.3 cm |
The reference values come from the CDC 2000 growth charts, published by the US Centers for Disease Control and Prevention. The CDC publishes them as LMS parameters, which are the official way to describe a growth distribution that is skewed rather than normally distributed. From the three parameters:
M is the median (the 50th percentile value), S is the coefficient of variation and L is the skewness power that bends the distribution into the right shape. The percentile is then the standard normal cumulative distribution at z: percentile = Φ(z) × 100.
Age is interpolated linearly between the published half-month rows, then rounded to the nearest half month. Interpolation in the middle of a 0.5-month gap introduces far less error than the measurement error of a home height or weight reading, which is typically 0.5–1 cm and 0.1–0.2 kg.
| Age | Correct reference | Why |
|---|---|---|
| 0–2 years | WHO growth standards | CDC and the AAP recommend WHO charts for under-2s because they describe how healthy, breastfed infants grow rather than how a mixed US sample grew. |
| 2–20 years | CDC 2000 growth charts | The reference used on this page, and the one US pediatric offices plot against past age 2. |
Mixing the two produces a visible step at age 2, which is exactly the artefact the CDC warns about. If your child is close to that boundary, keep every measurement on the same chart.
Anywhere between the 5th and the 95th percentile can be entirely normal. The 50th is the median, not a target; what matters is whether a child follows a steady curve over time rather than the position of one measurement.
Pediatric guidance generally flags a height below the 3rd percentile, or a height that crosses downward through two or more percentile lines over time. Either is a reason to discuss it with a pediatrician rather than a diagnosis in itself.
Not necessarily. Children often shift percentile bands during growth — many catch up during puberty — so a mid-childhood percentile predicts adult height only loosely. Mid-parental height is the better single predictor.
A rough estimate of genetic height potential: add the parents' heights and divide by two, then add 6.5 cm (2.5 in) for boys or subtract 6.5 cm for girls. Most children end up within about 8.5 cm (3.5 in) either side of that figure.
For ages 2–20 in the US, yes. For under-2s the WHO standards are recommended instead, and children of different ethnic backgrounds still use the same CDC charts because the CDC growth charts are not ethnicity-specific.