Height Calculator

This is a children's adult height prediction calculator based on a linear regression analysis method or parent's height.

Modify the values and click the calculate button to use
Child's Age
Child's Gender
Child's Height
feet   inches
Child's Weight pounds
Mother's Height
feet   inches
Father's Height
feet   inches
Child's Height cm
Child's Weight kg
Mother's Height cm
Father's Height cm

Predicting Based on the Parents' Heights Only

This calculator uses the parents' height only. It can be used to predict the future heights of unborn children or very young infants.

Mother's Height
feet   inches
Father's Height
feet   inches
Mother's Height cm
Father's Height cm

Height Converter

The following converter can be used to convert the body height between the metric unit and the unit used in the United States.

US unit convert to metric unit:
feet   inches

Metric unit convert to US unit:
cm

How tall will I be?

"How tall will I be?" or "how tall will my child be?" are questions that are often asked. The height of a person is determined by a combination of genetics and environmental factors. The precise contribution from these two factors is complex. Some studies suggest that genetics contributes 60%-80%. Normally, a child's height is based on parental heights subject to regression toward the mean. This means that very tall or short parents are likely to have a taller or shorter child than average, but the child is likely to be closer to the average height than their parents.

Other important factors that contribute to a child's adult height include nutrition, health, sports activities, health and age of the mother during pregnancy, etc.

Infants and toddlers grow the fastest. The growth rate declines rapidly from birth to roughly age 2 and declines more slowly thereafter. During puberty, the growth rate increases again to a second maximum, after which it slowly declines to zero. This is typically referred to as the pubertal growth spurt. On average, female and male growth trails off to zero at about 15 and 18 years old, respectively.

In some cases, a person's height begins to shrink in middle age, though shrinkage of stature is largely universal in the very elderly. This is due to factors such as the decreased height of intervertebral discs as well as changes due to degenerative diseases.

Predicting a child's adult height

Many different methods have been developed to predict a child's adult height, some more accurate than others. Regardless of how accurate the method, height prediction is not an exact science, and it is possible that a child's height can deviate significantly from what is predicted.

Bone age, skeletal maturity method

Bone age can be used to predict height and is considered more accurate than the other methods listed below. One such method is the Greulich-Pyle method that involves left hand and wrist radiographs to measure bone age. This method compares the radiograph of the patient to that of the nearest standard radiograph in the Greulich-Pyle atlas, a compilation of bone age data. Based on bone age, the height of the child, and the data compiled in the atlas, it is possible to predict height based on the percentage of height growth remaining at a given bone age. Note that the data in the atlas were obtained between 1931 and 1942 from Caucasian children, which may limit how accurately the Greulich-Pyle method can be used for current children.1

The Khamis-Roche method2

The Khamis-Roche method is considered to be one of the more accurate height prediction methods that do not require the measurement of bone age. It is based on the child's stature, weight, and the average stature of the two parents. The first calculator above is mainly based on this method.

Note that it is most applicable to Caucasian children between the ages of 4 and 9 who are free from any growth-related condition or disease.

Using growth charts

CDC Growth Charts of the United States are good sources of information to evaluate the growth situation of a child. These growth charts consist of percentile curves illustrating the distribution of specific body measurements of children in the United States. In total, there are 16 charts that contain data that can be used to compare the growth of a child over time. Measurements such as height, weight, and head circumference of a child can be compared to the expected values based on data from these growth charts of children of the same age and sex. In general, children maintain a fairly constant growth curve, which is why these charts can be used to predict the adult height of a child to a certain extent.

Simple methods

There are also some very simple, but less accurate, methods available. One of them is adding 2.5 inches (7.6 cm) to the average of the parent's height for a boy and subtracting 2.5 inches (7.6 cm) for a girl. The second calculator above is based on this method.

Another simple method is to double the height achieved by the child by age 2 for a boy, or age 18 months for a girl.

How to get taller?

Height, for better or for worse, is largely (60-80%) determined by genetics. As mentioned above, very tall parents are more likely to have a taller child, while very short parents are more likely to have a shorter child, with the child being more likely than their parents to be closer to average height. After the growth spurt during puberty, which differs slightly for girls and boys, neither will typically grow much more, and girls typically stop growing by 15, while boys stop at around 18 years of age.

That being said, there are environmental factors that can affect the height of a child. Some of these may be within the control of the child, while many may not. Nutrition and health of the mother during pregnancy can affect the height of their unborn child. Nutrition as well as exercise after birth can also affect height.

Recommendations for providing the best conditions for your body to grow follow typical guidelines for healthy living (in no particular order):

  1. Eat as many unprocessed foods as possible such as fresh fruits, vegetables, whole grains, proteins, and dairy.
  2. Avoid eating foods that are high in sugar, trans fats, saturated fats, and sodium.
  3. Exercise regularly to strengthen bones and muscles, maintain a healthy weight, and reduce the risk of diseases such as osteoporosis and other issues that could arise from poor health, which could in turn affect growth and height.
  4. Pay attention to good posture. Aside from looking shorter due to poor posture, it can affect actual height in the long term if the back starts curving to accommodate a regular slouching posture.
  5. Sleep regularly. Human growth hormone, a factor that affects growth, is released while you sleep. A regularly poor sleeping schedule during adolescence can affect growth in the long term. How much a person should sleep is dependent on their age, with more sleep being recommended the younger the child is.

In fringe cases, it is possible that some disease or condition could be hampering your growth, and it is possible that a doctor may be able to assist you in such a case, which may in turn affect height. For the most part however, peak height is reached by the time a child has gone through puberty, and it is likely that any child past puberty will maintain their height throughout adulthood.


  1. Mari Satoh, "Bone age: assessment methods and clinical applications", Clinical Pediatric Endocrinology, 2015
  2. Khamis HJ, Roche AF, "Predicting adult stature without using skeletal age: the Khamis-Roche method", Pediatrics, 1994

TL;DR

A height calculator estimates stature from limb measurements, parental genetics, or growth trajectory data—useful when direct measurement is impractical or when projecting adult height for adolescents. The tool provides orientation, not diagnosis; its value lies in flagging when a measured or predicted value deviates meaningfully from population norms, prompting timely clinical follow-up rather than replacing it.


Why Bone Age Matters More Than Calendar Age

The human skeleton does not grow on a birthday schedule. Two fourteen-year-olds can sit in the same classroom while one has completed ninety percent of skeletal maturation and the other has barely reached seventy percent. This divergence—between chronological age and biological bone age—represents the single most powerful hidden variable that renders naive height prediction unreliable.

Bone age assessment requires a left-hand wrist X-ray compared against standardized atlases. Without this input, calculators relying solely on current height and parental stature apply population-average maturation rates that may misclassify late bloomers as growth-impaired or early developers as genetically tall. The trade-off most users miss: simpler calculators sacrifice precision for accessibility, and that precision loss is asymmetric. Underestimating remaining growth potential in a late-maturing adolescent carries different implications than overestimating it in an early-maturing one.

For adults, height calculators shift function entirely. Limb-length estimations—femur, tibia, humerus—allow anthropometric reconstruction when direct measurement is impossible, such as in certain clinical populations or field settings. Here the hidden variable is body proportion variance. Sitting height ratio differs substantially across populations, and calculators using generic segment ratios introduce systematic error that compounds when applied to individuals far from the reference population mean.

The clinical relevance of any height output depends entirely on what question you are actually asking. Screening for growth disorders? Tracking nutritional intervention response? Estimating medication dosing? Each purpose demands different accuracy thresholds and different complementary data.


How Height Calculators Work: Methods, Margins, and Misapplications

Three primary methodologies power height estimation tools, each with distinct error profiles and appropriate use cases.

Genetic target (mid-parental height) calculators average parental stature with sex-specific adjustments. The formula structure is straightforward: for males, [(mother’s height + father’s height + 5 inches) / 2]; for females, [(mother’s height + father’s height - 5 inches) / 2], with results convertible between measurement systems. The non-obvious limitation: regression toward the mean means children of extremely tall or short parents typically land closer to population average than the formula suggests. This statistical shrinkage is often omitted in basic implementations.

Growth trajectory calculators for children require serial measurements—typically height recorded at multiple time points plotted against percentile curves. Velocity of growth matters more than absolute position. A child tracking consistently along the twenty-fifth percentile likely reflects genetic programming; the same child dropping from the fiftieth to twenty-fifth over eighteen months warrants evaluation. The trade-off: these tools demand longitudinal data most families lack, and they cannot distinguish constitutional delay from pathologic growth failure without additional clinical context.

Limb-segment estimators apply regression equations from forensic and sports science literature. Femoral length provides the strongest single-bone prediction, but even optimal equations carry standard errors that translate to several centimeters of uncertainty. For athletic populations, segment proportions diverge further from reference samples due to self-selection and training adaptations.

Population Category Typical Application Key Limitation Complementary Metric Needed
General pediatric screening Growth monitoring, early puberty assessment Assumes average bone age progression Bone age X-ray if trajectory shifts
Athletic/selected populations Body composition analysis, equipment fitting Segment ratios differ from reference populations Sport-specific proportion norms
Adult clinical/forensic Unmeasurable patients, remains identification High individual variance in body proportions Multiple segment cross-validation
Geriatric populations Nutritional status, sarcopenia screening Height loss from spinal compression unaccounted Measured vs recalled height comparison

The critical distinction between standard and athletic populations appears in that table’s middle rows. Elite swimmers, for instance, disproportionately exhibit longer upper segments; elite weightlifters often show relatively shorter limb lengths. Applying generic equations to these groups systematically misestimates stature, which then cascades into body mass index miscalculation and misclassified metabolic risk.


When Height Outputs Demand Action: Clinical Ranges and Risk Stratification

Height exists on a continuum, but clinical decision-making requires thresholds. The following framework synthesizes WHO growth standards for children and CDC reference data for adults, translated into actionable interpretation zones.

Classification Pediatric Stature-for-Age Adult Implications Recommended Response
Markedly below expected range Below 3rd percentile or crossing >2 percentile lines downward May indicate childhood growth failure with adult sequelae; associated with higher cardiovascular and metabolic risk in some studies Pediatric endocrinology referral; adult: comprehensive metabolic assessment
Lower end of typical range 3rd-25th percentile, stable velocity Usually genetic programming; adult height may limit certain occupational exposures Monitor growth velocity; ensure nutritional adequacy
Typical range 25th-75th percentile, consistent trajectory No height-specific health implications Routine maintenance
Upper typical range 75th-97th percentile Tall stature generally neutral for health; extreme heights may carry joint and circulatory considerations Monitor for disproportionate growth suggesting syndromic causes
Markedly above expected range Above 97th percentile or rapid acceleration Requires exclusion of growth hormone excess, genetic syndromes Pediatric endocrinology referral; adult: cardiovascular screening if recent change

The risks of falling outside healthy ranges are asymmetric and age-dependent. In children, persistent short stature may signal hypothyroidism, growth hormone deficiency, celiac disease, or chronic inflammatory conditions—each treatable if identified. Tall stature in childhood, conversely, more often represents familial pattern but requires exclusion of precocious puberty or rare genetic conditions.

For adults, the health implications of height itself are modest compared to height change. Measured height loss exceeding typical age-related decrement—roughly one to two centimeters per decade after age forty—signals vertebral compression, osteoporosis, or spinal pathology warranting evaluation. The decision shortcut: compare current measured height to peak adult height, not to population averages.

The trade-off most miss: height calculators optimized for population screening generate false reassurance in individual cases. A child’s predicted adult height landing within the “typical” range does not exclude underlying pathology if the trajectory to reach that prediction involved abnormal velocity or timing.


Measurement Accuracy and the Limits of Estimation

No calculator replaces a stadiometer in trained hands. The gap between tool output and true stature arises from multiple sources that users rarely consider.

Measurement technique error dominates real-world inaccuracy. Morning height exceeds evening height by up to two centimeters due to spinal disc hydration changes. Shoes, posture, and positioning introduce further variance. A calculator taking a self-reported “about five-ten” cannot distinguish between a morning measurement in sneakers and an evening measurement barefoot.

Reference population mismatch introduces systematic bias. Most calculators embed growth curves derived from specific geographic and temporal samples. Applying these to populations with different genetic backgrounds, nutritional histories, or environmental exposures generates predictable distortion.

Temporal validity matters for longitudinal tools. Growth patterns shift across generations—secular trends in earlier maturation and increased adult stature mean equations developed decades ago may misproject contemporary children.

Complementary metrics that improve interpretation include:

  • Weight and body mass index — but only with height measured, not estimated
  • Arm span — particularly valuable when lower extremity measurement is unreliable; arm span approximates height in typical proportions but diverges in certain conditions
  • Sitting height ratio — distinguishes limb length from trunk length contributions
  • Growth velocity — change over time, not single-point measurement

3-Step Action Plan for Different Result Levels

Step 1: Calibrate Your Input

Before trusting any output, verify your measurement. Use a wall-mounted stadiometer or flat surface against a wall with a right-angle object. Measure in the morning when possible. Record to the nearest millimeter, not centimeter. For parental height inputs, measure living parents directly rather than relying on recalled or driver’s license values—systematic overreporting of male height and underreporting of female height is well-documented.

Hypothetical example for demonstration: A user inputs mother’s measured height of 162 cm, father’s measured height of 178 cm, and child’s current height at age 11 of 138 cm. A mid-parental target calculator yields a genetic target of approximately 175 cm for a male child, with a typical statistical range spanning roughly 167-183 cm. The current height at the 25th percentile for age with normal growth velocity would be consistent with this projection.

Step 2: Interpret Within Context

For children: Compare current percentile to genetic target percentile. Large discrepancies suggest either measurement timing issues or genuine evaluation needs. Crossing percentile lines—especially downward—outweighs absolute position.

For adults: Compare current measured height to historical peak. Documented loss exceeding age-appropriate decrement triggers bone density and spinal evaluation regardless of absolute height.

For limb-based estimates: Cross-validate with multiple segments. Consistent convergence across femur, tibia, and humerus increases confidence; divergence suggests proportion atypia requiring population-specific equations.

Step 3: Determine Follow-Up Depth

Calculator Output Scenario Action
Within expected range, stable trajectory, no symptoms Continue routine health maintenance; recalculate annually for children
Near threshold, mild discrepancy, no other concerns Repeat with standardized measurement; review in 3-6 months for children
Clear deviation from genetic target or prior trajectory Schedule clinical evaluation; bring growth records and measurement dates
Adult with documented height loss from peak Request bone density assessment and vertebral imaging if clinically indicated

The One Shift: Treat Height as a Vital Sign, Not a Destiny

Height calculators serve poorly as fortune-telling devices and well as screening instruments. The reader should abandon the search for a single predicted number and instead adopt the practice of tracking height dynamics—velocity, trajectory, and change from individual baseline. A child growing consistently along their personal curve matters more than which percentile that curve occupies. An adult maintaining stable measured height matters more than how that height compares to a population average. The calculator’s proper role is generating the data points that make these dynamics visible, not delivering verdicts.


This Calculator Shows Direction, Not Advice

This calculator shows direction, not advice. For decisions involving your health, consult a licensed physician who knows your situation. The outputs described here are estimates and orientations, not diagnoses or treatment recommendations. Individual growth patterns, medical histories, and clinical contexts vary widely; no automated tool can substitute for personalized medical evaluation.