Child Height Predictor

What is Child Height Prediction?

This calculator does two separate things. First, it shows where your child's current height sits on the CDC 2000 stature-for-age growth chart, as a percentile among children of the same age and sex. Second, it estimates adult height from the parents' heights using the mid-parental method. The percentile is a measurement against a reference population; the adult height is an estimate based on genetics alone.

The mid-parental height method uses parents' heights to estimate adult height. For boys, the formula is: ((Mother's height + Father's height + 5) / 2). For girls: ((Mother's height + Father's height - 5) / 2). The range shown is ±2 inches, but actual adult height can fall outside it. For tracking weight growth, see our Growth Percentile Calculator to monitor overall growth patterns.

How to Use This Calculator

Enter the child's sex, current age (2-20 years), current height in inches, and both parents' adult heights in inches. The calculator reports the child's stature-for-age percentile and z-score from the CDC 2000 growth charts, predicts adult height with the mid-parental method (with a ±2 inch range), and estimates growth remaining as the predicted adult height minus the current height. Ages outside 2-20 are not covered by the CDC charts and are rejected.

The chart draws a straight line from the child's current height to the mid-parental estimate at age 18. Real growth is not linear (it speeds up during the pubertal growth spurt and then stops), so treat the line as a visual guide to the gap, not a forecast of height at any particular age.

Formula Explained

Current height percentile (CDC LMS method). The CDC publishes L (skewness), M (median) and S (coefficient of variation) for each sex and month of age. Age in years is converted to months and L, M and S are linearly interpolated between the nearest table rows. Height is converted to centimeters (X), then:

Predicted adult height (mid-parental method). An estimate based on the parents' heights:

The growth remaining figure is only as good as the mid-parental estimate behind it. It does not use the child's percentile, growth rate, or bone age.

When to Use This Calculator

Use this calculator to estimate a child's adult height for general curiosity, growth tracking, or understanding growth patterns. It's helpful for parents who want to understand their child's growth trajectory and set realistic expectations about adult height. For comprehensive growth tracking, use our Growth Percentile Calculator alongside this tool.

Parents and healthcare providers use height predictions to track growth, identify potential growth concerns, and understand how a child's height compares to genetic potential. However, predictions are estimates and actual height may vary.

Tips for Best Results

• Use accurate measurements: Ensure current height and parent heights are measured accurately. Use a stadiometer or wall-mounted measuring device for best accuracy.
• Understand the range: Predictions provide a range of ±2 inches. Actual adult height may fall anywhere within this range or occasionally outside it.
• Enter age precisely: The percentile changes month to month, so use a decimal age (for example 7.5 for seven and a half) rather than rounding to whole years.
• Watch the percentile over time: Most children stay near the same percentile as they grow. A child who crosses major percentile lines up or down may warrant medical evaluation.
• Focus on health: While genetics determine most of height, ensure adequate nutrition, sleep, and overall health to support optimal growth within genetic potential.
• Track weight growth: Use our Growth Percentile Calculator to monitor weight alongside height for complete growth tracking.

Frequently Asked Questions