This tool estimates a child’s likely adult height from both parents’ heights using the well-established mid-parental height method used by paediatricians. It is a quick, evidence-based way to get a realistic expectation for how tall a child may grow, complete with the natural range around the estimate.
How it works
The method combines the two parents’ heights and adjusts for the child’s sex, because adult men are on average about 13 cm taller than adult women. For heights in centimetres:
Boy: (mother + father + 13) ÷ 2 Girl: (mother + father − 13) ÷ 2
The tool then shows a likely range of ±8.5 cm around the estimate, since roughly 95% of children fall within that band. Imperial heights are converted to centimetres first, and results can be displayed in either unit.
Example
A boy with a mother of 165 cm and a father of 178 cm:
(165 + 178 + 13) ÷ 2 = 356 ÷ 2 = 178 cm
So his predicted adult height is about 178 cm, with a likely range of roughly 169.5 cm to 186.5 cm. For a girl with the same parents, the estimate would be (165 + 178 − 13) ÷ 2 = 165 cm.
This is a statistical guide, not a guarantee. Everything is calculated in your browser.