What is the Mid-Parental Height method?

The Mid-Parental Height (MPH) method, sometimes called the Tanner method, averages both parents' heights and adjusts by 2.5 inches (6.4 cm) upward for boys or downward for girls. The result is the genetic target height; the expected range is ±2 inches (±5 cm) of that target.

What is the Khamis-Roche method?

The Khamis-Roche method uses regression equations derived from the Fels Longitudinal Study. It incorporates the child's current height, weight, and both parents' heights as predictors. This calculator uses the height-only variant (without weight) which is somewhat less precise but still more accurate than the MPH method for most ages between 4 and 17.

How accurate are these predictions?

The MPH method has a standard error of roughly 2 inches (5 cm). Khamis-Roche typically achieves a standard error of 1.5–2 inches (3.8–5 cm). Neither method accounts for nutrition, illness, or early/late puberty timing — so treat the result as a range, not a precise forecast.

What age range does this tool cover?

The Khamis-Roche coefficients are validated for ages 4–17. For children aged 2–3 the Mid-Parental Height estimate is shown as the primary result; Khamis-Roche is applied but carries higher uncertainty. The tool notes this when the child's age is below 4.

Does this replace a doctor's assessment?

No. Growth disorders, hormonal conditions, or nutritional deficiencies can all affect height regardless of parental genetics. If your child's growth curve is abnormal, consult a pediatrician or pediatric endocrinologist.

Can I enter heights in centimeters?

Yes. Use the unit toggle at the top of the form to switch between US customary (feet and inches) and metric (centimeters). All calculations are done in centimeters internally.

Child Adult Height Predictor

Name: Child Adult Height Predictor
Availability: InStock
Author: Nham Vu

Enter parent heights, your child's current height, age, and sex to predict their adult height using two evidence-based formulas.

Units

Father's height

Mother's height

Child's sex

Child's age (years)

Child's current height

Fill in all fields and click Predict Adult Height.

Summary

Enter parent heights, your child's current height, age, and sex to predict their adult height using two evidence-based formulas.

How it works

Enter the father's and mother's heights (feet/inches or cm).
Enter the child's current height and select their sex.
Enter the child's age in years (2–17).
The Mid-Parental Height formula averages parent heights and applies a sex correction (+/−2.5 in) to produce a target range.
The Khamis-Roche formula uses regression coefficients derived from the Fels Longitudinal Study to refine the prediction.
Both estimates are displayed side by side so you can see the range.

Use cases

Get a ballpark adult height estimate at a pediatric checkup.
Understand how parental height influences a child's growth potential.
Compare two established prediction methods to see the likely range.
Track how current height aligns with expected adult height over time.
Discuss growth concerns with a pediatrician using quantitative context.
Help a child understand their projected height in a fun, educational way.

Frequently Asked Questions

Last updated: 2026-07-22 · Reviewed by Nham Vu