Child height calculator
Enter both parents' heights to estimate how tall your child is likely to be as an adult. It uses the mid-parental height method doctors use as a first estimate, and shows the range most children end up in.
Predicted adult height
about 5 ft 11 in (179 cm)
Likely range: 5 ft 7 in to 6 ft 2 in
Mid-parental height method. Most children end up within this range, but it is an estimate, not a promise.
How to use it
- Choose whether your child is a boy or a girl.
- Enter the mother's and father's heights. Measured heights work better than remembered ones, which tend to run a little high.
- Read the predicted height and, more importantly, the likely range around it.
How the prediction works
The calculator uses Tanner's mid-parental height formula from 1970, which doctors still use routinely. For a boy, add 13 cm to the mother's height, add the father's height and divide by two. For a girl, take 13 cm off the father's height, add the mother's height and divide by two.
The 13 cm is roughly the average height difference between men and women. With a mother of 165 cm and a father of 180 cm, for example, a boy's target is (165 + 13 + 180) ÷ 2 = 179 cm and a girl's is (180 − 13 + 165) ÷ 2 = 166 cm.
How accurate is it?
The likely range is the target plus or minus 8.5 cm, about two standard deviations, so most children end up inside it. That spread reflects how much children of the same parents differ from one another.
The formula has known blind spots. It doesn't allow for the way average height has risen over the past century, and studies in several countries have found it tends to underestimate adult height by around 1.5 to 2.5 cm. It is also less reliable when a parent is very short or very tall, and when parents' heights are remembered rather than measured.
Predicted adult height for boys
| Mother ↓ / Father → | 5′6″ | 5′8″ | 5′10″ | 6′0″ | 6′2″ | 6′4″ |
|---|---|---|---|---|---|---|
| 5′0″ | 5′6″ | 5′7″ | 5′8″ | 5′9″ | 5′10″ | 5′11″ |
| 5′2″ | 5′7″ | 5′8″ | 5′9″ | 5′10″ | 5′11″ | 6′0″ |
| 5′4″ | 5′8″ | 5′9″ | 5′10″ | 5′11″ | 6′0″ | 6′1″ |
| 5′6″ | 5′9″ | 5′10″ | 5′11″ | 6′0″ | 6′1″ | 6′2″ |
| 5′8″ | 5′10″ | 5′11″ | 6′0″ | 6′1″ | 6′2″ | 6′3″ |
| 5′10″ | 5′11″ | 6′0″ | 6′1″ | 6′2″ | 6′3″ | 6′4″ |
Rows are the mother's height and columns the father's. Each cell is the target height, the middle of a range of about 8.5 cm either way.
Predicted adult height for girls
| Mother ↓ / Father → | 5′6″ | 5′8″ | 5′10″ | 6′0″ | 6′2″ | 6′4″ |
|---|---|---|---|---|---|---|
| 5′0″ | 5′0″ | 5′1″ | 5′2″ | 5′3″ | 5′4″ | 5′5″ |
| 5′2″ | 5′1″ | 5′2″ | 5′3″ | 5′4″ | 5′5″ | 5′6″ |
| 5′4″ | 5′2″ | 5′3″ | 5′4″ | 5′5″ | 5′6″ | 5′7″ |
| 5′6″ | 5′3″ | 5′4″ | 5′5″ | 5′6″ | 5′7″ | 5′8″ |
| 5′8″ | 5′4″ | 5′5″ | 5′6″ | 5′7″ | 5′8″ | 5′9″ |
| 5′10″ | 5′5″ | 5′6″ | 5′7″ | 5′8″ | 5′9″ | 5′10″ |
What else shapes a child's height
- Genes set the broad range, which is why the parents' heights are the best simple predictor.
- Good nutrition and general health in childhood help a child reach that potential, while long-term illness can hold growth back.
- Doctors judge growth from a child's own measurements plotted on a growth chart over time, not from a single prediction.
Frequently asked questions
How tall will my child be?
A simple estimate is the mid-parental height: average the parents' heights, then add 6.5 cm for a boy or take off 6.5 cm for a girl. Most children end up within about 8.5 cm either side of that figure.
How accurate is the mid-parental height method?
It gives a range rather than an exact answer. The target sits in the middle of a range of plus or minus 8.5 cm, about two standard deviations, so it is a useful starting point, but some children still end up outside it.
Why does the formula add or subtract 13 cm?
Men are on average about 13 cm taller than women, so each parent's height is first adjusted to the child's sex. The real difference varies between populations, which is one reason the result is only an estimate.
Will my child be taller than us?
Possibly. Average height has risen over the past century and the formula doesn't allow for it, so studies have found it tends to underestimate adult height slightly. Sons also tend to be taller than their mothers, simply because of the difference between the sexes.
Does my child's current height matter?
This calculator uses only the parents' heights. Doctors also look at the child's own measurements over time on a growth chart, and sometimes at an X-ray of the hand to judge bone age, to see whether growth is on track.
When should I talk to a doctor about my child's height?
If your child seems much shorter or taller than the family pattern suggests, or their growth seems to slow down or drift across growth chart lines, ask your doctor. They will measure and chart growth over time.
Sources
- Tanner, Goldstein & Whitehouse (1970), Archives of Disease in Childhood: Standards for children's height at ages 2–9 years allowing for height of parents
- MSD Manual Professional: Height potential, a child's target height based on midparental height
- Ciancia et al. (2025), BMC Pediatrics: How accurate is Tanner's formula in estimating target height?