Height Calculator
- Likely range (about 95% of children)
- 5 ft 6.9 in – 6 ft 1.6 in
- Projection from current growth
- 5 ft 10.4 in (178.9 cm)
- Mid-parental target height
- 5 ft 10.1 in (178 cm)
- Share of adult height reached so far
- 62.6%
- Child's current BMI
- 14.5 kg/m²
An estimate only. Growth spurts, puberty timing, nutrition and health conditions can move a child well above or below it. Ask a pediatrician to plot your child on a growth chart if you have concerns.
Predicting Based on the Parents' Heights Only
Without a child's measurements, the mid-parental method gives a target height for a son and a daughter from the parents' heights alone.
- Son's likely range
- 5 ft 5.2 in – 5 ft 11.9 in
- A daughter's predicted adult height
- 5 ft 3.4 in (161.1 cm)
- Daughter's likely range
- 5 ft 0.1 in – 5 ft 6.8 in
Height Converter
- …which is also
- 1.651 m · 65 in
- 178 cm equals
- 5 ft 10.08 in
- …in inches
- 70.08 in
This height calculator estimates a child's adult height from their current growth and their parents' heights. Two smaller tools below give a parents-only prediction and convert heights between feet and centimeters.
How tall will I be?
Adult height is set mostly by genes. Studies of twins and families suggest that roughly 60% to 80% of the variation in height between people is inherited, which is why tall parents tend to have tall children. Hundreds of gene variants each nudge height up or down a little; there is no single height gene.
The remaining share comes from the environment a child grows up in. Good nutrition in pregnancy and childhood, enough sleep, and freedom from chronic illness let a child reach the height their genes allow. Average heights in many countries rose by several centimeters over the twentieth century as diets and health care improved, even though the gene pool barely changed.
Most girls stop growing between about 14 and 16, a year or two after their first period. Most boys keep growing until 16 to 18, and a few add a little more into their early twenties. Growth ends when the growth plates near the ends of the long bones close, and after that point height cannot increase.
Predicting a child's adult height
There are several ways to estimate how tall a child will be, and they differ in what information they need and how accurate they are.
The simplest is the mid-parental height, also called the target height. Average the parents' heights, then add 6.5 cm (about 2.5 inches) for a boy or subtract the same amount for a girl. Most children end up within about 8.5 cm (3.3 inches) of this figure. Its weakness is that it ignores the child entirely, so a child who is already unusually tall or short for their age is not taken into account.
Another rough rule is to double a child's height at age two for boys, or at about 18 months for girls. It works because children reach roughly half of their adult height around that age, but the rule is only a ballpark figure.
More accurate methods use the child's own growth. Doctors plot height on growth charts from the Centers for Disease Control and Prevention (CDC) or the World Health Organization; a child who has tracked along the same percentile line for several years will usually stay near it. The Khamis-Roche method combines a child's current height and weight with the parents' heights using age-specific regression coefficients, and methods based on bone age from a hand X-ray, such as Bayley-Pinneau, are more accurate still because they show how much growing time is left.
This calculator blends two of these ideas. It projects the child's current height forward by assuming they keep the same share of median adult height as on the CDC growth charts, then averages that projection with the mid-parental target. Treat the result as a reasonable guess with a margin of several centimeters, not a promise. Early or late puberty in particular can make a child look ahead of or behind schedule for a few years.
Boy: (mother + father + 13 cm) ÷ 2 · Girl: (mother + father − 13 cm) ÷ 2
- 13 cm
- about 5 inches, the average difference between adult men and women
- ± 8.5 cm
- the range within which about 95% of children finish
The main calculator averages this mid-parental target with a projection of the child's current height along the median CDC growth curve.
How to get taller?
Once growth plates have closed, no diet, supplement, stretching routine or device can make bones longer. Products promising to increase adult height are not supported by evidence. What children and teens can do is give their bodies the conditions to reach their full genetic potential.
Nutrition comes first. Growing children need enough total energy and protein, plus calcium, vitamin D, zinc and iron. A varied diet with dairy or fortified alternatives, eggs, fish, meat or legumes, whole grains, fruit and vegetables covers these for most children. Long-term undernutrition and some chronic illnesses, such as untreated celiac disease, are well-known causes of stunted growth.
Sleep matters because growth hormone is released mainly during deep sleep. The table shows the amount of sleep that pediatric sleep experts recommend at each age.
Regular physical activity builds strong bones and muscles and supports a healthy weight. Avoiding smoking, alcohol and anabolic steroids in the teenage years also protects growth. Adults cannot add height, but good posture, core and back strength, and maintaining bone density can stop them from losing height to slouching or osteoporosis later in life.
If a child is growing much more slowly than their peers, drops across percentile lines, or is far shorter than the parents' heights would suggest, see a doctor. Conditions such as growth hormone deficiency, hypothyroidism and Turner syndrome are treatable, and treatment works best when it starts early.
| Age | Recommended sleep per 24 hours |
|---|---|
| 4–12 months | 12–16 hours (including naps) |
| 1–2 years | 11–14 hours (including naps) |
| 3–5 years | 10–13 hours (including naps) |
| 6–12 years | 9–12 hours |
| 13–18 years | 8–10 hours |
| Adults | 7 or more hours |
Frequently asked questions
How accurate are adult height predictions?
Most methods that do not use a bone-age X-ray are accurate to within about 5 to 8 cm (2 to 3 inches) for most children. Predictions are least reliable just before and during puberty, when children mature at very different rates.
What is the mid-parental height formula?
For a boy, add the mother's and father's heights, add 13 cm (5 in) and divide by 2; for a girl, subtract 13 cm instead. With a 165 cm mother and a 178 cm father, a boy's target is (165 + 178 + 13) ÷ 2 = 178 cm. Most children finish within about 8.5 cm of this genetic target.
When do children stop growing?
Girls usually stop between 14 and 16 and boys between 16 and 18, although some boys grow slightly into their early twenties. Growth ends when the growth plates in the long bones fuse.
Can a child grow taller than both parents?
Yes. Height depends on many gene variants that combine differently in each child, and better nutrition and health than the parents had can also add height.
How do I convert 5 feet 5 inches to centimeters?
Multiply the total inches by 2.54. Five feet five inches is 65 inches, and 65 × 2.54 = 165.1 cm.
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