Child Height Predictor
Predict your child's adult height online for free with our child height predictor. Enter the biological father's and mother's heights and select the child's gender to get a predicted adult height using both the Mid-Parent (Tanner) and Khamis-Roche formulas. Includes the full 95% prediction range (±8.5 cm). Supports metric and imperial units — no signup required, all calculations run locally in your browser.
Enter the biological father's and mother's heights and select the child's gender to predict the child's adult height. Uses the Mid-Parent (Tanner) and Khamis-Roche formulas with a ±8.5 cm (±3.35 in) 95% prediction interval. All calculations run instantly in your browser — no signup required.
Father's Height
Mother's Height
Why Use Our Child Height Predictor?
Instant Child Height Predictions
Predict your child's adult height instantly in your browser with zero wait time. Our child height predictor runs both the Mid-Parent (Tanner) and Khamis-Roche formulas simultaneously and delivers results in milliseconds.
Secure Child Height Predictor Online
All height predictions run locally in your browser. Your parental height data never leaves your device, ensuring 100% privacy every time you use our child height predictor online.
Child Height Predictor - No Installation
Use our child height predictor directly in any browser with no downloads, plugins, or software required. Predict your child's adult height from any device, completely free.
Two Formulas with 95% Prediction Range
Our child height predictor compares the Mid-Parent (Tanner) and Khamis-Roche formulas side by side and shows the full 95% prediction interval (±8.5 cm / ±3.35 in) so you understand the realistic range of outcomes.
Common Use Cases for Child Height Predictor
Parental Curiosity & Planning
Expectant and new parents use our child height predictor to get a statistical estimate of their child's adult height based on their own heights. The prediction helps with long-term planning for activities like sports and clothing.
Sports & Athletic Potential Assessment
Parents and coaches use our child height predictor to estimate whether a child may have the height advantage for sports like basketball, volleyball, or swimming. The 95% prediction range gives a realistic picture of potential adult stature.
Paediatric Growth Monitoring
Healthcare providers use the mid-parent height formula as a reference point when monitoring a child's growth trajectory. Our child height predictor provides the same calculation used in clinical settings, instantly.
Family Height Comparison
Families use our child height predictor to compare predicted heights across siblings with different parent combinations, or to understand how much of their own height their children are likely to inherit.
Educational & Research Reference
Students and researchers studying human genetics and growth patterns use our child height predictor to explore the mid-parent height formula and understand how parental genetics influence offspring stature.
Adoption & Blended Family Planning
Adoptive parents and blended families use our child height predictor to understand the genetic height potential of biological parents when that information is available, providing context for a child's growth expectations.
Understanding Child Height Prediction
What is a Child Height Predictor?
A child height predictoris a tool that estimates a child's predicted adult height based on the heights of their biological parents. The most widely used method is the Mid-Parent Height Formula(developed by Tanner in 1970), which calculates a target height by averaging the parents' heights and applying a gender-based adjustment. Our child height predictor also runs the Khamis-Roche formula as a second estimate and averages both results for a more robust prediction. The tool shows the full 95% prediction interval (±8.5 cm) so you understand the realistic range of outcomes — not just a single number. All calculations run locally in your browser with no data sent to any server.
How Our Child Height Predictor Works
- 1. Enter Parental Heights: Enter the biological father's and mother's heights in centimetres or feet and inches. Select the child's gender — the gender adjustment is applied differently for boys and girls in both formulas.
- 2. Instant Dual-Formula Calculation: Click Predict Height and the calculator instantly runs both the Mid-Parent (Tanner) and Khamis-Roche formulas. The average of both predictions is shown as the primary estimate. All calculations happen locally in your browser.
- 3. View Prediction with 95% Range: See the predicted adult height alongside the 95% prediction interval (±8.5 cm). The range shows the realistic spread of outcomes — 95% of children with these parental heights will fall within this range.
Height Prediction Formulas Explained
- Mid-Parent Height Formula (Tanner, 1970): Boy: (Father's height + Mother's height + 13 cm) ÷ 2. Girl: (Father's height + Mother's height − 13 cm) ÷ 2. This is the most widely used clinical formula for predicting adult height from parental heights. The 13 cm adjustment accounts for the average height difference between adult males and females.
- Khamis-Roche Formula (simplified): Boy: Mid-parent height + 6.5 cm. Girl: Mid-parent height − 6.5 cm. Where mid-parent = (Father + Mother) ÷ 2. The Khamis-Roche method was developed using longitudinal growth data and provides a complementary estimate to the Tanner formula.
- 95% Prediction Interval (±8.5 cm): The ±8.5 cm (±3.35 in) range represents the 95% prediction interval for the mid-parent formula. This means that 95% of children with the given parental heights will have an adult height within this range. The remaining 5% will fall outside due to genetic variation, nutrition, and other factors.
- Factors That Influence Actual Height: Genetics accounts for approximately 60–80% of height variation. The remaining 20–40% is influenced by nutrition (especially protein and calcium intake during childhood), sleep quality (growth hormone is released during deep sleep), physical activity, and overall health. Chronic illness or nutritional deficiency can significantly reduce height potential.
What the Child Height Predictor Shows
- Predicted Adult Height: The average of the Mid-Parent and Khamis-Roche predictions — the single best estimate of the child's adult height.
- 95% Prediction Range: The low and high estimates (±8.5 cm from the average) representing the range within which 95% of children with these parental heights will fall.
- Formula Comparison: Both the Mid-Parent (Tanner) and Khamis-Roche predictions shown side by side so you can see how the two methods compare.
- Height Context: A note comparing the predicted height to global average adult heights for the child's gender.
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Frequently Asked Questions About Child Height Predictor
A child height predictor is a tool that estimates a child's predicted adult height based on the heights of their biological parents. Our child height predictor uses the Mid-Parent (Tanner) and Khamis-Roche formulas with a 95% prediction interval, running instantly in your browser with no signup required.
The mid-parent height formula is accurate to within ±8.5 cm (±3.35 in) for 95% of children. This means the actual adult height will fall within the predicted range 95% of the time. The remaining 5% of children will be taller or shorter due to genetic variation, nutrition, and other environmental factors.
The Mid-Parent Height Formula (Tanner, 1970) calculates predicted height as: Boy = (Father + Mother + 13 cm) ÷ 2; Girl = (Father + Mother − 13 cm) ÷ 2. The 13 cm adjustment accounts for the average height difference between adult males and females. It is the most widely used clinical formula for height prediction.
The Khamis-Roche formula is an alternative height prediction method that uses mid-parent height with a gender adjustment: Boy = mid-parent + 6.5 cm; Girl = mid-parent − 6.5 cm. It was developed using longitudinal growth data and provides a complementary estimate to the Tanner formula.
No — the mid-parent formula only uses parental heights and the child's gender. It does not require the child's current height or age. For a more precise prediction that accounts for the child's current growth trajectory, a paediatrician can use bone age X-rays and growth chart percentiles.
Yes — genetics accounts for approximately 60–80% of height variation. The remaining 20–40% is influenced by nutrition (especially protein and calcium during childhood), sleep quality (growth hormone is released during deep sleep), physical activity, and overall health. Adequate nutrition during childhood can help a child reach their full genetic height potential.
Absolutely. Our child height predictor runs entirely in your browser. The parental heights you enter are never sent to any server or tracked in any way. Everything stays completely private on your device.
Yes — our child height predictor is 100% free with no signup, no account, no premium tier, and no usage limits. Predict your child's adult height as many times as you need, completely free forever.
The mid-parent formula requires the biological parents' heights because it is based on genetic inheritance. For adopted children, if the biological parents' heights are known, the formula can still provide a useful estimate. If biological heights are unknown, the formula cannot be applied accurately.