Estimate a child’s adult height using parent heights, with results in feet, inches, and centimeters.
Enter the details to estimate adult height.
Predicted adult height
Khamis-Roche estimate
Typical estimate range
Height prediction is an estimate, not a guarantee.
How we calculated this
The Khamis-Roche method was developed using data from healthy white American children, so prediction accuracy may vary for children from other populations.
Height predictions are estimates and are not a medical assessment.
How this height calculator works
This calculator uses the mid-parental-height method: a quick estimate based on the heights of a child’s biological parents and the child’s sex. It gives a useful central estimate and a typical range, but it cannot predict an exact adult height. Growth patterns, puberty timing, health, nutrition, and ordinary individual variation all matter.
How tall will my child be?
Parents’ heights are one of the strongest clues to likely adult height, which is why the calculation starts there. A child can still end up taller or shorter than the estimate. Puberty can begin and progress at different times, growth spurts vary, and measurements themselves are not always exact. Treat the result as a starting point for curiosity, not a promise about a child’s future growth.
How parent height predicts adult height
The mid-parental formula adjusts the average of the parents’ heights by 13 cm to reflect typical sex-related height differences:
Boys(Father + Mother + 13 cm) ÷ 2
Girls(Father + Mother − 13 cm) ÷ 2
For example, a father who is 178 cm and a mother who is 163 cm give a central estimate of 177 cm for a boy: (178 + 163 + 13) ÷ 2. The calculator shows a typical estimate range of about 8.5 cm on either side of that central figure.
What is the Khamis-Roche method?
The detailed estimate uses the Khamis-Roche method, which predicts adult stature without a bone-age X-ray. It combines a child’s age, sex, current height, current weight, and both parents’ heights using regression coefficients that change by age and sex. The method was developed using data from healthy white American children, so prediction accuracy may vary for children from other populations.
How accurate is a height calculator?
No height calculator can determine a child’s final adult stature exactly. Genetics, puberty timing, growth spurts, general health, nutrition, measurement error, and the population used to develop a prediction method can all affect the result. This tool intentionally describes its range as an estimate, not as a guarantee or medical assessment.
What affects adult height?
Genetics. Parents strongly influence a likely height range.
Sex. Typical growth patterns differ, which is why the formula has separate adjustments.
Puberty. Its timing and duration vary from child to child.
Nutrition and health. Adequate nutrition and general health support normal growth, but this calculator does not diagnose growth concerns.
How to measure height accurately
- Remove shoes and stand on a hard floor against a wall.
- Keep heels flat, stand upright, and look straight ahead.
- Place a level object on top of the head and mark the wall.
- Measure from the floor to the mark, then measure a second time if unsure.
Use the parents’ adult heights where possible. A small measuring difference can shift the central estimate.
Feet and inches to centimeters
| Feet and inches | Centimeters |
|---|---|
| 5 ft 0 in | 152 cm |
| 5 ft 2 in | 157 cm |
| 5 ft 4 in | 163 cm |
| 5 ft 6 in | 168 cm |
| 5 ft 8 in | 173 cm |
| 5 ft 10 in | 178 cm |
| 6 ft 0 in | 183 cm |
| 6 ft 2 in | 188 cm |
| 6 ft 4 in | 193 cm |
Height prediction example
For a boy with a father who is 5 ft 10 in (about 178 cm) and a mother who is 5 ft 4 in (about 163 cm), the formula is (178 + 163 + 13) ÷ 2. That gives a central estimate of about 177 cm, or about 5 ft 10 in. It is a useful midpoint, not a guaranteed final height.
Height predictions are estimates and are not a medical assessment. For concerns about a child’s growth, consult a pediatrician or qualified healthcare professional.
Questions
How tall will my child be?
Parent heights can provide a useful central estimate, but they cannot predict an exact adult height. Puberty timing, health, nutrition, and individual variation also matter.
How accurate is a height calculator?
It is an estimate, not a guarantee. The result gives a likely central height based on parent heights and shows a typical range around it.
What is the mid-parental height formula?
For boys, add the parents’ heights and 13 cm, then divide by two. For girls, subtract 13 cm before dividing by two.
What is the Khamis-Roche method?
It estimates adult stature from age, sex, current height, current weight, and parent heights using age- and sex-specific regression coefficients. It was developed using data from healthy white American children, so accuracy may vary for other populations.
Can parents accurately predict a child’s height?
Parents’ heights are an important clue, but no formula can account for every influence on growth or predict a final height perfectly.
Can a child be taller than both parents?
Yes. A central estimate is not a limit. Children can be taller or shorter than either parent.
Does nutrition affect height?
Adequate nutrition supports normal growth, alongside genetics and overall health. This calculator is informational and does not assess a child’s health.
How do I convert feet and inches to centimeters?
Multiply the total number of inches by 2.54. For example, 5 ft 10 in is 70 inches, or about 178 cm.
Why is height prediction only an estimate?
Growth spurts, puberty timing, health, measurement differences, and ordinary individual variation mean a child’s adult height cannot be known in advance.
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