How Tall Will My Child Be?
How tall will my child be? This height predictor estimates the genetic target height for a boy or a girl from the heights of mother and father and shows the usual range. It is a guide, not a forecast.
Example: Father’s height 71 cm / in · Mother’s height 66 cm / in · Child’s sex: Boy · Unit: Inches → Target height: Target height about 180 cm (usual range 172–189 cm). Source: Lipman TH et al. (2015): Electronic Health Record Mid-Parental Height Auto-Calculator for Growth Assessment in Primary Care, Clinical Pediatrics (formula: mean of the parents' heights, boys + 13 cm, girls − 13 cm, divided by 2). Updated: .
How it is calculated
If the father is 180 cm (5 ft 11 in) and the mother 168 cm (5 ft 6 in), the genetic target height is 180.5 cm for a boy and 167.5 cm for a girl; the usual range is ± 8.5 cm in each case. The calculator uses the Tanner formula, which pediatrics uses as a guide to genetic growth potential.
How it is calculated
First the average of mother’s and father’s height is taken. Men are about 13 cm taller than women on average, so 6.5 cm are added for a boy and 6.5 cm subtracted for a girl. The result is the target height. Around it lies a range of ± 8.5 cm, about two standard deviations: most children reach an adult height inside this range.
What the target height cannot do
- It says nothing about the course: a child can grow earlier or later and still reach the same adult height.
- It does not replace a growth chart. Your pediatric practice judges your child’s height compared with peers using percentiles.
- It is only rough: nutrition, health and the trend toward taller generations affect adult height. Studies from other countries found adults who grew taller than calculated.
More family calculators: the BMI calculator, the due date calculator and the length converter for centimeters and inches.
Frequently asked questions
How tall will my child be?
The genetic target height is the average of the parents’ heights plus 6.5 cm for boys and minus 6.5 cm for girls, with a range of about ± 8.5 cm. It is a guide, not an exact prediction.
How accurate is the target height?
Most children end up inside the range, but an individual child can differ. Nutrition, health and generation play a part. Some studies found adults taller than calculated.
Can I predict height from my child’s current height?
That takes growth charts and expertise, which this calculator cannot provide. Your pediatric practice judges growth using percentiles.
Should I measure the parents’ heights?
Yes, measured values are better. In one study men overstated their height by 1.6 to 2.5 cm and women by 0.5 to 1.0 cm.
Sources and legal basis
- Lipman TH et al. (2015): Electronic Health Record Mid-Parental Height Auto-Calculator for Growth Assessment in Primary Care, Clinical Pediatrics (formula: mean of the parents' heights, boys + 13 cm, girls − 13 cm, divided by 2)
- Ouarezki Y et al. (2017): Measured parental height in Turner syndrome, European Journal of Pediatrics (target range of the parents: 8.5 cm = 2 standard deviations)
- Kim et al. (2024): Tanner’s target height formula underestimates final adult height in Korean adolescents, BMJ Paediatrics Open (limits of the formula)
As of: · Editorial policy
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