Height Calculator
Adult Height Predictor works out Predicted adult height and Low end of the likely range from Method, Child's sex and Units. The default figures on this page give predicted adult height of 179.0 cm; change any entry and the result, the working and the sources update together.
Your figures
Updates as you typeHow this is worked out
2 steps
- Mid-parental height (boy) = (father + mother + 13 cm) / 2 = (180 + 165 + 13) / 2 = 179 cm.
- Target range = 179 +/- 8.5 cm = 170.5 to 187.5 cm.
Its 4 worked examples are re-run on every release, last on 15 September 2026. What changed
Sources and references
4 sources
What the Adult Height Predictor calculates
Predicts a child's adult height from the parents' heights (Tanner mid-parental target height), from the doubling rule, or from the Khamis-Roche regression using its published coefficients.
How to use this Adult Height Predictor
Enter Method, Child's sex, Units and Father's height. Predicted adult height updates as you type, and “Use a worked example” loads checked figures you can adjust. Change one figure at a time to see what drives the result.
How the result is worked out
Open “How this is worked out” beside the result for the step-by-step calculation behind Predicted adult height, Low end of the likely range and High end of the likely range.
The method follows Tanner JM, Goldstein H, Whitehouse RH. Standards for children's height at ages 2-9 years allowing for height of parents. Arch Dis Child 1970;45:755-762, Royal College of Paediatrics and Child Health, UK-WHO growth chart guidance: parental height comparator and target range, Khamis HJ, Roche AF. Predicting adult stature without using skeletal age: the Khamis-Roche method. Pediatrics 1994;94:504-507 and Nemours KidsHealth, Growth charts and predicting adult height.
Mid-parental target height, boy, 180 cm father and 165 cm mother example
With Method: mid-parental, Child's sex: male, Father's height: 180, Mother's height: 165, the calculator returns Predicted adult height: 179, Low end of the likely range: 170.5, High end of the likely range: 187.5. This example is checked against an independent source in the test suite.
What you can compare
Change one input at a time to see how it affects Predicted adult height, Low end of the likely range and High end of the likely range. The inputs you can vary are Method, Child's sex, Units, Father's height, Mother's height and Child's current height.
Understanding Predicted adult height, Low end of the likely range and High end of the likely range
A predicted adult height is a statistical estimate with a wide error band, not a measurement. Tanner's target range spans about 17 cm, and the Khamis-Roche standard error is roughly 5.6 cm for boys and 4.3 cm for girls. Short stature, a falling height percentile or delayed puberty should be assessed by a clinician, not by a calculator.
Results are general information, not financial, tax, legal, medical or engineering advice. Check any decision that matters with a qualified professional.
See something wrong? Report a problem with this calculator
Frequently asked questions
What information do I need for the Adult Height Predictor?
You need Method, Child's sex, Units, Father's height, Mother's height, Child's current height, Child's current weight and Child's age. The page opens with default figures that give predicted adult height of 179.0 cm, so you can see the scale before entering your own.
What does this Adult Height Predictor show?
It shows Predicted adult height, Low end of the likely range, High end of the likely range, Mid-parental (target) height, Share of predicted adult height reached, Growth still to come and Method, with the working and any warnings for your entries.
Can I check how the Adult Height Predictor result was calculated?
Yes. The “How this is worked out” section shows the calculation steps, and the sources section identifies the references used for the method.