How tall will your child be? This free height calculator predicts a child’s adult height from both parents’ heights using the mid-parental method, with a likely range around the estimate.
Parents’ heights
cm
cm
ftin
ftin
Predicted adult height
—
Enter both parents’ heights
Likely range (±)
—
Mid-parental height
—
Child’s sex
Boy
Method
Mid-parental
An estimate based on parents’ heights — genetics, nutrition and health all play a part, so actual adult height can differ. Ask a pediatrician for growth concerns.
Use this free height calculator to predict a child’s adult height from the parents’ heights. Enter the mother’s and father’s height and the child’s sex to see an estimated grown-up height and likely range.
What this height calculator shows you
A height calculator estimates how tall a child is likely to be as an adult, based mainly on genetics. This one uses the widely known mid-parental method: it averages both parents’ heights and adjusts for the child’s sex, then shows a predicted height and a likely range around it.
How adult height is predicted
Mid-parental = (mother + father) ÷ 2
Boys = mid-parental + 6.5 cm
Girls = mid-parental − 6.5 cm
For a mother of 165 cm and father of 180 cm, the mid-parental height is 172.5 cm — so a son is predicted at about 179 cm and a daughter at about 166 cm. Most children land within roughly ±8.5 cm of the estimate.
How to use the height calculator
Select the child’s sex.
Choose your units (cm or feet/inches).
Enter both parents’ heights.
Read the result. The predicted adult height and range appear instantly.
What affects a child’s height
Genetics is the biggest factor — hence using parents’ heights.
Nutrition during growth years matters a great deal.
Sleep and general health support healthy development.
Timing of puberty shifts when growth happens, though not always the final height.
Height terms glossary
Term
What it means
Mid-parental height
The average of the two parents’ heights.
Predicted height
The estimate after the sex adjustment.
Likely range
The band most children fall within (about ±8.5 cm).
Growth chart
A pediatric tool tracking growth over time.
Height Calculator FAQ
How do you predict a child's adult height?
The mid-parental method averages both parents' heights, then adds about 6.5 cm for a boy or subtracts 6.5 cm for a girl. For parents of 165 cm and 180 cm, that predicts roughly 179 cm for a son and 166 cm for a daughter.
How accurate is the prediction?
It's a genetic estimate, so most children fall within about ±8.5 cm of the figure. Nutrition, health and other factors mean actual adult height can land above or below it.
Why does the calculator ask for the child's sex?
On average, men are taller than women, so the method adjusts the mid-parental height up for boys and down for girls to give a more accurate estimate.
Can a child be taller than both parents?
Yes. Height reflects many genes plus environment, so children can end up taller or shorter than both parents. The prediction is a central estimate, not a ceiling.
What else affects how tall a child grows?
Beyond genetics, nutrition, sleep, overall health and the timing of puberty all influence growth. Persistent growth concerns are best discussed with a pediatrician.
Is the height calculator free to use?
Yes, this height calculator is completely free, needs no sign-up, and gives instant results directly in your browser.
