Predicted adult height
This is the mid-parental height method. Most children end up within about 8.5 cm (3.3 in) of this figure, but nutrition, health and other factors also play a part.
How the prediction works
The calculator uses the mid-parental height formula, which doctors use to estimate a child’s target height:
- Boys: (mother’s height + father’s height + 13 cm) divided by 2
- Girls: (mother’s height + father’s height minus 13 cm) divided by 2
The 13 cm (about 5 inches) reflects the average difference in adult height between men and women.
How accurate is it?
It is an estimate. Most children reach an adult height within about 8.5 cm (3.3 in) above or below the predicted figure. Nutrition, sleep, health conditions and the timing of puberty all play a part.
When to talk to a doctor
If your child is much shorter or taller than expected for their family, or their growth seems to slow down or speed up, mention it at their next check-up. Regular measurements on a growth chart are the best way to follow growth.
Frequently asked questions
Can I predict height for a baby?
Yes, the mid-parental method only needs the parents’ heights. Your child’s own growth pattern over time adds more information.
Is the 2 years times 2 rule accurate?
A common saying is that adult height is about twice the height at age 2. It is a rough guide only; the mid-parental method is used more often by doctors.
Is my information saved?
No. The calculation runs in your browser and nothing is stored.