Height Calculator
Predict a child's adult height from parents' heights using established medical formulas. Useful for context, not for medical decisions.
How to use the Height Calculator
- Enter your inputs into the Height Calculator above.
- Results update instantly as you type — no submit button needed.
- Adjust any value to see how the result changes in real time.
The mid-parental height formula
Boy: ((Father + Mother + 5 in) / 2) · · · Girl: ((Father + Mother − 5 in) / 2)
The mid-parental height (MPH) gives an estimate. Actual adult height typically falls within ±4 inches of this prediction. The 5-inch adjustment reflects the average male-female height difference.
Worked example
Father 5'10" (70"), mother 5'5" (65"). For a son: (70 + 65 + 5)/2 = 70 inches = 5'10". For a daughter: (70 + 65 − 5)/2 = 65 inches = 5'5". Most adults end up within ±4 inches.
Frequently asked questions
How accurate is the prediction?
About ±4 inches (10 cm) for ~95% of cases. Nutrition, health and other genetic factors not captured in parental heights add significant variance.
Are there better predictors?
Bone age via X-ray (Greulich-Pyle or Tanner-Whitehouse methods) is more accurate but requires a clinical visit. Growth percentile tracking through childhood is also informative.
When does a child reach final height?
Most girls finish growing by 14–16; most boys by 16–18. Growth plates close completely by the early 20s. Late growth spurts are normal and not predictable.