# Child Height Percentile Calculator

URL: https://speedycalculator.com/calculators/health/child-height-percentile/
Last updated: 2026-10-30

> The child height percentile calculator compares a child's height with the CDC growth charts for age and sex (2–20 years) and gives the percentile, z-score and the median height for that age.

## Inputs

- Sex
- Age (years, months)
- Height (cm, in, m, ft, mm)

## Results

- Height-for-age z-score
- Height percentile
- Percentile group
- Median height for age

## Formula

```
z = ((height ÷ M)^L − 1) ÷ (L × S), with CDC stature-for-age LMS values
Percentile = Φ(z) × 100
```

## Explanation

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

FieldWhat to enterSexChoose one: Male, FemaleAgeUnits: years, monthsHeightUnits: 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 (%)4100699849105121e-1169e-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.*

## Worked 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.

## FAQ

**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.


## Sources

- [CDC – Clinical growth charts and LMS data files](https://www.cdc.gov/growthcharts/cdc-growth-charts.htm)