Child Adult Height Predictor
Estimate how tall a child may be as an adult. It uses the mid-parental (Tanner) formula from the parents' heights, gives a likely range, and compares the child with the typical height for their age.
Written by Suhaib Hassan. Figures are estimates you can edit. Our methodology.
It averages the parents' heights with a sex adjustment, adds a range of 8.5 cm either side, and separately projects the child's current position against typical growth.
Parents ask this all the time. This shows the standard formula and its uncertainty rather than a single confident number.
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Typical height by age
Approximate median heights, rounded from the WHO and CDC growth references. Half of children are taller and half are shorter, and a healthy range is wide. Ask your doctor to plot your child on the official growth chart.
| Age | Boys | Girls |
|---|---|---|
| 2 years | 87 cm · 2' 10" | 86 cm · 2' 10" |
| 4 years | 103 cm · 3' 5" | 103 cm · 3' 5" |
| 6 years | 116 cm · 3' 10" | 115 cm · 3' 9" |
| 8 years | 128 cm · 4' 2" | 127 cm · 4' 2" |
| 10 years | 138 cm · 4' 6" | 138 cm · 4' 6" |
| 12 years | 149 cm · 4' 11" | 151 cm · 4' 11" |
| 14 years | 163 cm · 5' 4" | 160 cm · 5' 3" |
| 16 years | 173 cm · 5' 8" | 162 cm · 5' 4" |
| 18 years | 177 cm · 5' 10" | 163 cm · 5' 4" |
Formulas
How the numbers are worked out.
Mid-parental (Tanner) height
The average of the parents' heights, with 13 cm (5 in) added for a boy or taken off for a girl.
boy: (father + mother + 13) ÷ 2
girl: (father + mother − 13) ÷ 2Growth channel estimate
If a child stays at the same position against the typical height for their age, the adult height scales the same way. A rough guide only.
adult ≈ height now × (median adult ÷ median at this age)Likely range
Adult height is usually within about 8.5 cm (3.3 in) of the mid-parental target.
range = target ± 8.5 cmWorked examples
Illustrative figures, each checked by hand. The first is the default setup.
Boy aged 8½
Height 130.8 cm, father 180.3 cm, mother 165.1 cm (the default).
range 170.7 to 187.7 cm
Girl aged 10
Height 142 cm, father 178 cm, mother 165 cm.
Growth channel
A boy aged 10 at 145 cm.
145 × 177 ÷ 138 = 186 cm if he stays on that channel
How to predict a child's adult height
- Choose sex and units, then enter age and current height.
- Enter the biological father's and mother's heights.
- Read the mid-parental target and range.
- Compare it with the growth channel estimate. Differences are normal.
These are estimates for children growing normally. They cannot account for puberty timing, illness or nutrition. Talk to a paediatrician if you are worried about growth, or if a child is far above or below their growth chart, and rely on their measurements.
By Suhaib Hassan · Reviewed 29 September 2026 · How CalculatePilot verifies formulas →
Sources
- Tanner, J.M., Goldstein, H. & Whitehouse, R.H., Standards for children's height at ages 2 to 9 years allowing for height of parents, Archives of Disease in Childhood, 1970.
- Centers for Disease Control and Prevention, Clinical Growth Charts, stature-for-age.
- World Health Organization, Child Growth Standards (2006).
Frequently asked questions
How accurate is a height prediction?
The mid-parental method is usually within about 8.5 cm (3.3 in) of adult height. It cannot see the timing of puberty, so it is an estimate, not a promise.
How does the mid-parental formula work?
Add the parents' heights, add 13 cm for a boy or subtract 13 cm for a girl, and divide by two. The 13 cm is the average difference between adult men and women.
Does the child's current height change the estimate?
Not in the mid-parental method. The growth channel estimate does use it, by comparing the child's height with the typical height at their age.
When do children stop growing?
Girls usually stop growing around 14 to 16, and boys around 16 to 18, though this varies. Growth plates close after puberty.
What if my child is much taller or shorter than predicted?
Many healthy children are. If a child's growth crosses growth-chart lines or you are concerned, a paediatrician can assess it, sometimes with a bone age X-ray.
How feet, inches and centimetres convert: height calculator guide.
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