Height Calculator
Predict your child's adult height with our free calculator using the mid-parental formula and CDC growth data, plus percentiles and charts.
Quick-Fill Scenarios
Median height by age (CDC 2000)
CDC's median at each birthday: half of children that age are taller and half shorter.
| Age | Boy | Girl |
|---|---|---|
| 2 years | 2 ft 10 in | 2 ft 9.5 in |
| 3 years | 3 ft 1.4 in | 3 ft 1 in |
| 4 years | 3 ft 4.2 in | 3 ft 3.7 in |
| 5 years | 3 ft 6.9 in | 3 ft 6.4 in |
| 6 years | 3 ft 9.4 in | 3 ft 9.2 in |
| 7 years | 3 ft 11.9 in | 3 ft 11.8 in |
| 8 years | 4 ft 2.3 in | 4 ft 2.2 in |
| 9 years | 4 ft 4.6 in | 4 ft 4.3 in |
| 10 years | 4 ft 6.6 in | 4 ft 6.3 in |
| 11 years | 4 ft 8.5 in | 4 ft 8.7 in |
| 12 years | 4 ft 10.7 in | 4 ft 11.5 in |
| 13 years | 5 ft 1.5 in | 5 ft 1.9 in |
| 14 years | 5 ft 4.5 in | 5 ft 3.1 in |
| 15 years | 5 ft 6.9 in | 5 ft 3.7 in |
| 16 years | 5 ft 8.3 in | 5 ft 4 in |
| 17 years | 5 ft 9 in | 5 ft 4.1 in |
| 18 years | 5 ft 9.4 in | 5 ft 4.2 in |
| 19 years | 5 ft 9.5 in | 5 ft 4.3 in |
| 20 years | 5 ft 9.6 in | 5 ft 4.3 in |
Every method here is a statistical estimate, not a guarantee: genetics, nutrition, health and the timing of puberty all move a child's adult height, and the prediction methods apply to healthy children. Talk to a pediatrician about any concern with a child's growth.
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How to Predict a Child's Adult Height
Predicting how tall a child will grow is one of the most common questions parents ask. This height calculator — also known as a mid-parental height calculator — uses scientifically validated methods including the mid-parental height formula and CDC growth chart data to estimate a child's predicted adult height. Enter the parents' heights to get an instant prediction with a height range, or use the percentile calculator to see how your child compares to other children their age.
What Is the Mid-Parental Height Formula?
The mid-parental height formula, published by Tanner, Goldstein and Whitehouse in 1970, is the most widely used way to predict a child's adult height from the parents' heights. Average the parents' heights, then add 6.5 cm (2.5 inches) for a boy or subtract 6.5 cm for a girl: half of the 13 cm (5 inches) by which men and women differ. Adding 13 cm to the combined height for a boy, or subtracting it for a girl, and dividing by two gives the same result. Tanner's range of ±8.5 cm (about 3.3 inches) around that target covers the 3rd to 97th percentile of the heights such children reach. It needs nothing about the child, which is why pediatricians use it as a first check, and why the Khamis-Roche method, which adds the child's own height and weight, predicts more closely.
Mid-Parental Height Formula
Boys: (Mother's Height + Father's Height + 13 cm) ÷ 2 | Girls: (Mother's Height + Father's Height − 13 cm) ÷ 2How to Use the Height Calculator
Pick a method: Mid-parental (the parents' heights only), Khamis-Roche (the child's age, height and weight, plus both parents), Multiplier (the child's age and height), or Percentile (where the child stands on the CDC chart)
Choose the child's sex, and a unit for each height: centimeters, inches, or feet and inches
Enter the age in years and months where the method asks for it: Khamis-Roche covers 4 to 17½ years, the multiplier birth to 18 for boys and 17 for girls, the CDC chart 2 to 20
Read the prediction or percentile, with its range and the method's own error bounds
In Khamis-Roche mode, compare it with the multiplier and the mid-parental target for the same child
Open the step-by-step working to see every coefficient and multiplication
Common Height Calculator Use Cases
Curious Parents During Pregnancy
Expecting parents can use the mid-parental height formula to get a rough idea of their baby's future adult height based solely on their own heights.
Pediatric Well-Child Visits
Doctors routinely use mid-parental height and growth percentiles during check-ups to assess whether a child is growing normally.
Teen Growth Curiosity
Teenagers wondering 'how tall will I be?' can enter their current age and height to see a predicted adult height and when they'll likely stop growing.
Sports and Athletics Planning
Parents and coaches can estimate a child athlete's adult height to help with long-term sports development and position planning.
Growth Disorder Screening
If a child's height percentile is unusually low or high, it may prompt further medical evaluation for conditions affecting growth.
Family Height Comparisons
Compare predicted heights for siblings or see how a child's predicted height compares to family members and population averages.
Height Unit Conversion
Enter a height in feet and inches and read it in centimeters as well, or the other way round: every result shows both.
Why Use a Height Calculator?
Predict Your Child's Adult Height
Get an estimate from methods pediatric research published and tested: Tanner's target height, the Khamis-Roche prediction and Paley's multiplier, each computed from its paper's own coefficients.
Track Growth Percentiles
See where your child's height falls for age and sex on the CDC 2000 growth charts, computed from CDC's own LMS parameters for any month from 2 to 20 years, with the chart's curves drawn around it.
Identify Growth Concerns Early
A height outside the 3rd to 97th percentile curves the CDC chart prints is one pediatricians look at more closely, together with how the child has grown over time.
No X-Ray or Doctor Visit Needed
Bone-age methods such as Bayley-Pinneau need an X-ray. Khamis-Roche was built to predict nearly as well without one, from measurements you can take at home.
Compare Multiple Prediction Methods
In Khamis-Roche mode the page sets the multiplier and the mid-parental target beside the prediction, so you see how closely three methods agree for the same child.
Understand Growth Expectations
Learn when boys and girls typically stop growing, what factors affect height, and what range of heights is normal for your child's predicted outcome.
Enter Heights Your Way
Type heights in centimeters, in inches, or in feet and inches in two boxes, so 5 ft 10 in is never misread as 5.10 feet. Every result shows both units.
Frequently Asked Questions
Your parents' heights are the biggest single factor: MedlinePlus Genetics puts about 80% of height down to inherited DNA. The mid-parental formula turns them into a target. For a boy, add the parents' heights plus 5 inches (13 cm) and divide by 2; for a girl, subtract the 5 inches instead. Tanner's range around that target is ±3.3 inches (8.5 cm). If you know your current age, height and weight, the Khamis-Roche method narrows it: nine in ten children end within ±2.1 inches (boys) or ±1.7 inches (girls).
Without an X-ray, the Khamis-Roche method: nine in ten of its predictions fall within ±2.1 inches for boys and ±1.7 inches for girls, from the child's height, weight and both parents' heights. With a bone-age X-ray, clinicians use methods such as Bayley-Pinneau. The mid-parental formula is the simplest, with a range of ±3.3 inches (8.5 cm).
Use the mid-parental height formula: For boys: (mother's height + father's height + 5 inches) ÷ 2. For girls: (mother's height + father's height − 5 inches) ÷ 2. For example, if mom is 5'4" and dad is 5'10", a boy's predicted height = (64 + 70 + 5) ÷ 2 = 69.5 inches = 5'9.5".
Most boys are close to their adult height by 16. Paley's multipliers put a 16-year-old boy at about 98 percent of it (a multiplier of 1.021) and an 18-year-old at 99.5 percent (1.005). The fastest growth comes about two years after puberty starts, and late maturers can keep growing slowly into their late teens.
Most girls reach their adult height by 15 or 16, about two years after their first period. Paley's multipliers put a 15-year-old girl at over 99 percent of adult height (1.008), and his table ends at 17, when growth is complete. Girls enter puberty earlier than boys, which is why they stop growing earlier.
Largely, yes. MedlinePlus Genetics estimates that about 80% of a person's height is determined by inherited DNA variations. The rest reflects the environment, above all nutrition and health during childhood and adolescence: genetics sets the potential, and nutrition and health decide whether it is reached.
On the CDC 2000 growth charts the median 12-year-old boy is 149.1 cm (4 ft 10.7 in) and the median 12-year-old girl 151.2 cm (4 ft 11.5 in). Girls are often slightly taller at this age because they enter puberty earlier.
Choose Percentile, then enter your child's age, sex and height. The page uses CDC's own LMS parameters for that month of age, so the percentile is exact rather than read off a printed chart. The 50th percentile is the median: half of children that age are taller and half shorter. The CDC chart prints curves from the 3rd to the 97th percentile.
For most people, no. Growth plates in the bones close during late adolescence (typically 14-16 for girls, 16-18 for boys). Once closed, bones can no longer lengthen. However, some men may grow slightly until age 20-21. Daily height can vary up to 1 inch due to spinal disc compression.
On the CDC 2000 medians a child grows about 7 cm (2.8 in) between the third and fourth birthdays, about 6 cm (2.4 in) a year from 5 to 8, and about 5 cm (2 in) a year just before puberty, when the growth spurt starts. A pediatrician judges growth over several measurements, not one.
Tanner set its range at ±8.5 cm (about 3.3 inches) around the target, meant to hold the 3rd to 97th percentile of children. A 2024 study of 23 very large families (Zeevi and colleagues, in the journal Children) found that the standard formula explained 36% of the variation in adult height, and that children ended on average 2.7 cm taller than their target. It works best for parents of average height: children of very tall or very short parents tend to regress toward the mean.
A formula Khamis and Roche published in Pediatrics in 1994 that predicts adult stature from a child's current height, weight and mid-parent height, with coefficients for each sex at every half year from 4 to 17½, and no bone-age X-ray. Its weight coefficients were corrected in a 1995 erratum, and this calculator uses the corrected ones. Nine in ten predictions fall within ±2.1 inches for boys and ±1.7 inches for girls. It was developed on white American children of the Fels Longitudinal Study, without conditions that affect growth.
On the CDC 2000 growth charts the median 14-year-old boy is 163.8 cm (5 ft 4.5 in) and the median 14-year-old girl 160.4 cm (5 ft 3.1 in). This is the age where boys typically catch up with girls and pass them.
Yes. Inherited DNA accounts for about 80% of height (MedlinePlus Genetics), and nutrition is the largest part of the rest. Enough protein, calcium, vitamin D and overall energy during childhood and adolescence are needed to reach full height potential, and malnutrition during the growth years can permanently reduce adult height.
Yes, identical twins can differ in height by up to 1-2 inches despite sharing the same DNA. This happens because environmental factors like nutrition, illness, and physical activity during growth years create small differences. It demonstrates that even with identical genetics, height isn't 100% predetermined.
A method Paley and colleagues published in 2004: adult height is about the current height times a multiplier for the child's age and sex, built from CDC growth data. A 10-year-old boy's multiplier is 1.278, so a boy of 138 cm is predicted to reach about 176 cm. It needs no parents' heights and works from birth to 18 for boys and 17 for girls. In the authors' validation, 85% of boys' predictions were within 5 cm (2 inches) of adult height.
CDC's growth charts give three numbers for each sex and month of age: L, M (the median) and S. A child's z-score is ((height ÷ M)^L − 1) ÷ (L × S), and the percentile is the share of the normal distribution below that z-score. At z = 0 the child is exactly on the median, the 50th percentile; z = 1.88 is the 97th.