Height percentiles show how tall a child is compared with others of the same age and sex. Children usually follow their own percentile line; crossing two major percentile lines, or a height below the 3rd percentile, should be checked by a doctor.
How to use the Child Height Percentile Calculator
- Sex
- Age
- Height
Results update as you type, and every field accepts the units shown in its menu.
How it works
Enter sex, age and standing height.
Tips
- Measure lying length for babies under 2 and standing height from age 2.
- Use the exact age in months for babies – a few weeks matters.
- Follow the trend across several visits; crossing two major percentile lines is more important than one value.
- Discuss concerns with your paediatrician.
Common mistakes to avoid
- Comparing a baby with the wrong sex chart.
- Reading the 50th percentile as “normal” and everything else as abnormal.
- Using corrected age incorrectly for premature babies.
Inputs explained
| Field | What to enter |
|---|---|
| Sex | Choose one: Male, Female |
| Age | Units: years, months |
| Height | Units: cm, in, m, ft, mm |
Example values
How the main result changes when Age changes and everything else stays at the example values above:
| Age (years) | Height percentile (%) |
|---|---|
| 4 | 100 |
| 6 | 99 |
| 8 | 49 |
| 10 | 5 |
| 12 | 1e-1 |
| 16 | 9e-6 |
Health note: this calculator is for education and screening only and is not a diagnosis or treatment advice. Discuss your results with a qualified clinician.
Formula
z = ((height ÷ M)^L − 1) ÷ (L × S), with CDC stature-for-age LMS valuesPercentile = Φ(z) × 100Worked example
Inputs — Sex: Male; Age: 8 years; Height: 128 cm.
Results — Height-for-age z-score = -0.02; Height percentile = 49 %; Percentile group = 15th–50th; Median height for age = 128.1 cm.
Key terms
- Stature
- Standing height.
Frequently asked questions
What height percentile is normal?
Anything between about the 3rd and 97th percentile.
Does a low percentile mean a problem?
Not necessarily – short parents often have short, healthy children.
When should I see a doctor?
If height falls below the 3rd percentile or crosses two major lines.
What formula does the Child Height Percentile Calculator use?
z = ((height ÷ M)^L − 1) ÷ (L × S), with CDC stature-for-age LMS values.