Estimate a child’s adult height from the parents’ heights with the mid-parental (Tanner) method, with the likely range shown honestly.
How the prediction works
The mid-parental method is the classic paediatric estimate: average the parents’ heights, then add 6.5 cm for a boy or subtract 6.5 cm for a girl. It is a genetics-based ballpark — most children land within about 8.5 cm either side of it, which is why this calculator shows the range as prominently as the number.
How to use it
- Choose boy or girl.
- Enter the mother’s and father’s heights in centimetres.
- Read the predicted adult height, the likely range, and the feet-and-inches version.
The formula
A worked example
With a mother of 162 cm and a father of 176 cm, a boy’s prediction is (162 + 176 + 13) ÷ 2 = 175.5 cm — about 5′9″ — with a likely range of 167–184 cm. The same parents’ girl predicts 162.5 cm. Change any field and every figure updates as you type.
What this can and cannot tell you
Genetics sets most of the range; nutrition, sleep and health decide where in it a child lands. This is a general estimate for curiosity and planning — if a child’s growth curve worries you, the person to ask is a paediatrician, who will use the child’s own measurements over time rather than a formula.