Child's future height

How it works

The «mid-parental» method estimates adult height from the average of the parents' height: +13 cm for boys, -13 cm for girls, then divided by two. It's the indication most used by pediatricians.

Note

It's only an ESTIMATE with a ±8 cm margin: real height also depends on nutrition, health and individual genetics. Not medical advice.

Where the formula comes from

The «mid-parental» calculation, also called target height, comes from Tanner's growth studies and is the sum a paediatrician does in their head during a check-up. The idea is simple: height is largely inherited, so you average the two parents and shift that average thirteen centimetres up for a boy or down for a girl, because thirteen centimetres is roughly the average height difference between adult men and women.

Why the margin is so wide

The eight centimetres either way are not a token disclaimer: they are the spread actually observed. It means two siblings with the same parents can end up fifteen centimetres apart and both be perfectly normal.

Adult height depends on hundreds of different genes, and alongside them on nutrition, sleep, chronic childhood illness and above all on when puberty starts: early puberty closes the growth plates sooner and can take centimetres off a child who at eight looked tall for their age.

What the paediatrician actually watches

The parental estimate mainly serves as a benchmark. What matters is not the single number, but whether the child is growing along their own curve and whether that curve is consistent with the target height. A short child, with short parents and steady growth, is not a problem.

The situation that deserves a visit is a different one: the child who crosses percentiles, moving up or down through the lines on the chart, or who stops growing for months. There today's number counts for little; the direction counts.

Nearby tools

For growth year by year there are Growth percentiles and Baby age. For adults there are still BMI calculator and Ideal weight.