Child's Predicted Height
Take the average of both parents, then add 6.5 cm for a boy or subtract 6.5 cm for a girl. Actual adult height usually lands within about 8.5 cm either side.
Your numbers
Predicted height
175cm
Zone low
166.5cm
Zone high
183.5cm
Formula
Predicted height = (Father's height + Mother's height ± 13) ÷ 2
Genetics explains roughly 80% of height — sleep, nutrition and illness often push the result outside the range.
What to enter
| Input | Default | Accepted range |
|---|---|---|
| Father's heightThe father’s height, entered in centimetres. | 175 | 120 ~ 220 |
| Mother's heightThe mother’s height, entered in centimetres. | 162 | 120 ~ 220 |
| Sex (M1 / F0)Where the formula splits by sex — enter 1 for male, 0 for female. | 1 | 0 ~ 1 |
Step by step
Quick reference table
Results when only Father's height changes and everything else stays put.
| Father's height | Predicted height (cm) | Zone low (cm) | Zone high (cm) |
|---|---|---|---|
| 120 | 147.5 | 139 | 156 |
| 131 | 153 | 144.5 | 161.5 |
| 175 | 175 | 166.5 | 183.5 |
| 220 | 197.5 | 189 | 206 |
What each result means
| Result | At default values |
|---|---|
| Predicted height (cm)Adult height estimated from the parents, give or take about 5 cm. | 175 |
| Zone low (cm)The bottom of the heart-rate band. | 166.5 |
| Zone high (cm)The top of the heart-rate band. | 183.5 |
Common mistakes
Genetics explains roughly 80% of height — sleep, nutrition and illness often push the result outside the range.
Glossary
- Father's height
- The father’s height, entered in centimetres.
- Mother's height
- The mother’s height, entered in centimetres.
- Sex (M1 / F0)
- Where the formula splits by sex — enter 1 for male, 0 for female.
- Predicted height
- Adult height estimated from the parents, give or take about 5 cm.
- Zone low
- The bottom of the heart-rate band.
- Zone high
- The top of the heart-rate band.
Frequently asked questions
Q. How is Child's Predicted Height calculated?
Predicted height = (Father's height + Mother's height ± 13) ÷ 2 — Take the average of both parents, then add 6.5 cm for a boy or subtract 6.5 cm for a girl. Actual adult height usually lands within about 8.5 cm either side.
Q. Can you walk through an example?
With Father's height 175, Mother's height 162, Sex (M1 / F0) 1, the answer is Predicted height 175cm.
Q. What do I need to enter?
Enter Father's height, Mother's height, Sex (M1 / F0). The result recalculates as you type, and an empty box counts as zero.
Q. How much does the answer move if I change a number?
Changing only Father's height moves the answer to Father's height 120 → Predicted height (cm) 147.5 and Father's height 220 → Predicted height (cm) 197.5. The table below lays out five steps.
Q. How are the numbers rounded?
Money is shown to the nearest whole unit, percentages to one decimal place and everything else to two. What you see is rounded; the calculation itself carries the unrounded value forward.
Q. Anything to watch out for?
Genetics explains roughly 80% of height — sleep, nutrition and illness often push the result outside the range.
Related calculators
These calculators help you understand health figures; they do not replace diagnosis or prescription. See a clinician if you have symptoms.