Child Height Predictor

Predict adult height for a boy or girl from the heights of both parents and see the likely range.

Last updated:

Child's Predicted Height

Please enter the required details and click Calculate.

Predicting Based on the Parents' Heights Only

Please enter the parents' heights and the child's gender, then click Calculate.

Height Converter

Please enter a height to convert and click Convert.

Was this calculator helpful?

★ ★ ★ ★ ★
Embed this calculator

Calculation Examples

Calculation Case Result
Father 180 cm, Mother 165 cm (Boy) Target 179 cm, range about 170.5 to 187.5 cm
Father 180 cm, Mother 165 cm (Girl) Target 166 cm, range about 157.5 to 174.5 cm
Khamis-Roche Method Uses current height, weight, and mid-parent height, with no X-ray
Mihail Doncenco
Mihail Doncenco Site Creator & Calculator Expert

Founder and developer of CalcMate. Builds and maintains every calculator on this site, focusing on formula accuracy and clear, practical results.

How to Predict a Child's Future Height

Enter the child's sex and the measured height of both parents. The tool uses the mid-parental height (MPH) method, also called target height, which pediatric clinics use as a baseline when they judge growth. In centimeters: \[H_{boy} = \dfrac{H_{father} + H_{mother} + 13}{2}\] \[H_{girl} = \dfrac{H_{father} + H_{mother} - 13}{2}\] The 13 is the average height gap between adult men and women. Example: a father of 175 cm and a mother of 160 cm give 174 cm for a boy and 161 cm for a girl. Treat the result as the middle of a range. About 8.5 cm either side covers roughly 95% of expected outcomes.

Predicting Adult Height

Genetics explains most of the difference in adult height between people. Twin studies commonly put heritability at 60% to 80% or higher, depending on the population. The rest comes from nutrition, sleep, chronic illness, hormones, and conditions before birth. A well-fed child of tall parents will usually be tall, while untreated growth hormone deficiency, celiac disease, or long-term undernutrition can pull the result below the genetic target.

Growth follows a set pattern: fast gains in infancy, a steadier pace through childhood, then a pubertal growth spurt. In girls, peak growth typically comes around ages 11 to 13, and growth is largely done by 15 to 16. In boys, the peak comes around ages 13 to 15, and most reach final height by 17 to 19. The growth plates (epiphyseal plates) close at the end of puberty, and height stops increasing after that.

MPH works best as a baseline for tracking. If a child's measured height drifts outside the MPH range, or yearly growth slows, that is a reason to talk to a pediatrician.

Child growth projection chart based on mid-parental height

Useful Tips 💡

  • Measure in the morning, barefoot, with the back against a flat wall. The spinal discs compress during the day, so evening height can be 1 to 2 cm lower.
  • Measure the parents instead of asking them. Self-reported heights tend to run high, and a 2 cm error in one parent moves the target by 1 cm.
  • Use the range, not the midpoint. A target of 179 cm with 8.5 cm either side means 170.5 to 187.5 cm.

📋Steps to Calculate

  1. Enter the child's current age and both parents' measured heights.

  2. Select the child's gender.

  3. Click "Calculate" to receive the predicted adult height range based on the Mid-Parental Height formula.

Mistakes to Avoid ⚠️

  1. Treating the midpoint as a promise. Parents of 180 cm and 165 cm can have a son anywhere from about 170 to 188 cm, and roughly 1 child in 20 falls outside even that band.
  2. Using the formula after growth is finished. Once the growth plates have closed, the child's own measured height is the adult height.
  3. Entering a step-parent or adoptive parent. MPH relies on the biological parents' heights.
  4. Ignoring a medical cause. Celiac disease, thyroid disorders, or growth hormone deficiency can hold a child well below the genetic target.

Practical Applications📊

  1. Check a growth track: parents of 175 cm and 160 cm give a girl a target of 161 cm, with a range of about 152.5 to 169.5 cm. A girl heading well outside that band deserves a pediatric check.

  2. Spot slow growth early: measure every 6 to 12 months. A child who falls from the 50th percentile to below the 10th, crossing two major percentile lines, needs review.

  3. Set realistic expectations for sport or clothing: a boy with a target of 174 cm is most likely to finish between 165.5 and 182.5 cm.

Questions and Answers

Do environmental factors influence height predictions?

Yes, environment shapes roughly 20% to 40% of adult height. Enough protein, calcium, vitamin D, and zinc during childhood and the teen years lets a child reach the genetic target. Deep sleep matters because growth hormone is released mostly during it. Chronic illness, long-term undernutrition, and untreated hormone disorders can leave a child well below target. If measured height sits more than 8.5 cm under the MPH target, ask a pediatrician for an evaluation.

Does the height predictor work for girls?

Yes, for a girl you subtract 13 cm instead of adding it: \(\dfrac{H_{father} + H_{mother} - 13}{2}\). With the same parents (father 180 cm, mother 165 cm), the target is \(\dfrac{180 + 165 - 13}{2} = 166\) cm, with a range of about 157.5 to 174.5 cm. The 13 cm reflects the average adult height gap between men and women, which is close to 13 cm in most populations.

How accurate is a child height predictor?

Most children finish within about 8.5 cm of their MPH target, so the method gives a likely band and not a single number. Accuracy drops when a child has a growth disorder, long-term undernutrition, or a chronic illness. It also drops when a child's nutrition differs a lot from the parents' childhood, because average adult height has risen in many countries as nutrition improved. If a child ends up well outside the range, or growth slows, a pediatrician can check growth speed and bone age.

How can I track my child's growth over time?

Measure every 6 to 12 months in the same way, morning, barefoot, against a flat wall, and log each value with the date. Plot the points on a CDC chart (ages 2 to 20) or a WHO chart (under 2). A steady percentile track, such as staying near the 40th percentile, is reassuring even if the height looks low. A fall across two or more major percentile lines within 6 to 12 months, for example from the 50th to below the 10th, is a stronger signal than any single value. Bring it up with a pediatrician.

How do I predict height for a boy?

For a boy, add both parents' heights and 13 cm, then divide by 2: \(\dfrac{H_{father} + H_{mother} + 13}{2}\). Example: \(\dfrac{180 + 165 + 13}{2} = 179\) cm. About 95% of boys with these parents are expected to finish within 8.5 cm of that, which is 170.5 to 187.5 cm. Enter both heights in centimeters to get the target and range instantly.

How does the height calculator use growth charts?

It compares the target with standard growth charts, which plot height by age as percentile curves. CDC growth charts cover ages 2 to 20 years (2000 edition), and CDC recommends the WHO growth standards for children under 2 years. A target between the 3rd and 97th percentile is within the typical range. Example: a child tracking the 10th percentile with a target near the 50th is worth watching for growth speed, since the child may be catching up or falling behind.

What is a child height predictor and how does it work?

A child height predictor estimates adult height from the heights of both parents. It averages the two heights, then adds 6.5 cm for a boy or subtracts 6.5 cm for a girl, which is half of the 13 cm average gap between men and women. Example: parents of 180 cm and 165 cm give 179 cm for a boy and 166 cm for a girl. The answer is a target with a range of about 8.5 cm either side, not a forecast. It ignores nutrition, illness, and how the child has grown so far, so use it as a baseline.

What is the Mid-Parental Height formula?

The Mid-Parental Height (MPH) formula estimates genetic height potential from the parents' heights. For boys: \(\text{MPH} = \dfrac{\text{Father} + \text{Mother} + 13}{2}\). For girls: \(\text{MPH} = \dfrac{\text{Father} + \text{Mother} - 13}{2}\). All heights are in cm. Example: father 175 cm and mother 160 cm give 174 cm for a boy and 161 cm for a girl. Clinicians use it as a screening reference to judge whether a child's growth fits the family background. It is not a diagnosis.

Which formulas are used in the Height Calculator?

The main method is the sex-adjusted Mid-Parental Height formula: \(\dfrac{H_{father} + H_{mother} \pm 13}{2}\), with plus for boys and minus for girls. A second method, Khamis-Roche (Khamis and Roche, Pediatrics, 1994), predicts adult height from the child's current height, weight, and mid-parent height. It needs no X-ray. Methods that use bone age, such as Bayley-Pinneau, require a hand and wrist X-ray read by a clinician, and this tool does not use them.
Disclaimer: This calculator is designed to provide helpful estimates for informational purposes. While we strive for accuracy, financial (or medical) results can vary based on local laws and individual circumstances. We recommend consulting with a professional advisor for critical decisions.