You will get a predicted adult height with a range — for example: 178 cm (169–186).
A child’s adult height is about 80% determined by genetics, so you can estimate how tall a child will grow from the parents’ heights. This calculator uses the mid-parental height formula — a gauge of potential, not an exact forecast: nutrition, sleep, health and puberty all play a part too.
How the prediction works
- For a boy: (father’s height + mother’s height + 13) ÷ 2.
- For a girl: (father’s height + mother’s height − 13) ÷ 2.
- A range of ±8.5 cm is added — it covers about 95% of cases.
The 13 cm figure is the average height difference between adult men and women — that’s why it’s added for a boy and subtracted for a girl.
What else affects height
Genetics sets the channel, but it isn’t always reached in full. Final height is also shaped by good nutrition, enough sleep (growth hormone is released mostly during sleep), physical activity and general health. A sharp deviation from the “family” channel is worth checking with a paediatrician.
FAQ
How accurate is the prediction?
It’s a guide, not a guarantee. The ±8.5 cm range is fairly wide precisely because height depends on more than genes. Most children end up within this channel.
From what age can I calculate it?
Any age — the formula is based on the parents’ heights, not the child’s, so you can estimate the future height from birth.
Can I influence my child’s height?
You can’t dramatically “outgrow” genetics, but poor sleep, a lack of nutrition or chronic illness can stop a child reaching their potential. A healthy lifestyle helps a child grow into the upper part of their channel.