Height Predictor and Adult Height Calculator
Use this height calculator to estimate the future height of children, teenagers, and adults based on age, genetics, and growth patterns. This calculator uses the Khamis-Roche method, one of the most accurate height prediction models available. If your child is under four, or you are pregnant and curious about your baby's expected height, use the Mid-Parental Height Formula below instead, given below
Height Predictor
Khamis-RocheInstant height prediction using scientific growth models. Estimate predicted height based on age and parents
Parent's Height Only
Mid-ParentalEstimate predicted height using only parents' heights. Works for babies, very young children, and unborn babies too. If you are pregnant, enter both parents' heights to get your child's estimated adult height range.
Quick Height Converter
Convert cm to feet and inches, feet and inches to cm, or meters to feet instantly
How Does a Height Calculator Work?
A height calculator is a tool that combines current measurements (age, height, weight, and parental heights) and applies them to population growth data to produce a likely height range.
- 1. Enter measurements: child's age, current height, weight, and both parents' heights. More inputs produce more accurate results.
- 2. The model calculates: the calculator applies the growth formula to population data, adjusting for age, sex, and genetics.
- 3. Get a predicted height range: The result is a likely adult height estimate, shown as a range rather than a single exact number.
How Tall Will My Child Be?
No tool can predict a child's future height with complete certainty. However, research on child growth patterns makes it possible to estimate adult height with reasonable accuracy.
Modern height prediction calculators analyze three key factors:
responsible for 60-80% of final height.
Age, height, and weight measurements refine the estimate.
Growth patterns observed across large populations by age and sex.
The result is an estimated adult height range: a useful guideline, not a guarantee. Children's growth patterns are individual and can vary significantly based on health, nutrition, and timing of puberty.
How Tall Will I Be? Calculator for Teens & Adults
Teens asking "how tall will I be" can use the Khamis roche calculator. Enter your current age, height, weight, and your parents' heights for the most accurate estimate.
Teens (Under 18)
Growth plates are still open. The Khamis-Roche calculator gives the best estimate. Use current measurements for maximum accuracy.
- Most reliable between ages 4-17
- Accuracy improves as you get closer to adult height
- Boys often grow until 18; girls until 15-16
Adults (18+)
Growth plates close after puberty. For adults, height prediction is no longer relevant, but the Mid-Parental Height Formula can still estimate what height their children may reach.
- Adult height is already determined
- Use the Parent's Height tool to predict children's height
- Use the height converter for unit conversion
Important Limitation:No height calculator can account for medical conditions, growth hormone disorders, or premature puberty. If growth seems unusually fast or slow, consult a pediatrician.
Ready to get your height prediction? The calculator is at the top of this page.
Use the Height PredictorWhat Determines Height?
A child's final adult height is shaped by two factors: genetics and environment. Understanding both helps set realistic expectations for height prediction.
Genetics
Accounts for 60-80% of final height. Children of taller parents tend to be taller, but children of very tall or very short parents often grow closer to the average population height, a phenomenon called regression toward the mean.
Nutrition & Sleep
Remaining 20-40% comes from environment.
- Protein, Calcium, Vitamin D, Zinc
- 9-11 hrs sleep (School-age)
- 8-10 hrs for teenagers
Growth Timing
Early puberty may produce a taller child temporarily but a shorter adult. Late puberty often results in a longer growth window and greater final height.
Average Height by Age (Growth Charts)
CDC growth chartstrack average height and weight from birth to young adulthood, covering boys and girls from ages 2 through 18. They show where a child falls on the height percentile chart relative to peers.
The 50th percentile represents the median height for that age and sex. Healthy children typically fall between the 3rd and 97th percentile.
Note: Pediatricians focus less on a single measurement and more on whether a child stays on a consistent growth curve over time.
Height Calculator vs. Growth Charts
Different tools answer different questions. Use this comparison to understand when to use each method.
| Factor | Height Calculator | Growth Chart |
|---|---|---|
| Purpose | Predict future adult height | Track current growth vs peers |
| Data needed | Age, height, weight, parent heights | Age + current height |
| Best for | Parents, teens, curiosity | Monitoring growth over time |
| Requires doctor | No (use online) | No (use online) |
| Typical accuracy | ±2-4 inches | Shows percentile, not prediction |
| Works without parents | Partial (less accurate) | ✓ Yes |
When Do Boys Stop Growing?
Boys usually experience their main growth spurt during puberty.
The typical growth timeline for boys looks like this:
- early puberty begins around age 11-12
- rapid growth occurs between ages 13 and 15
- growth slows around 16-17
During peak puberty, boys can grow 3-4 inches per year. Most boys stop growing around age 18, although small increases may continue until around age 20.
When Do Girls Stop Growing?
Girls generally begin puberty earlier than boys.
Typical growth timeline:
- puberty begins around age 9-10
- growth spurt occurs between ages 10 and 14
Most girls reach their adult height between 15 and 16 years old. Because girls experience puberty earlier, they often appear taller than boys during late childhood.
Height prediction methods Explained
How to Predict Your Child's Height
Researchers use several formulas to estimate adult height. Each method balances accuracy against the data it requires.
Khamis-Roche Method
Considered the most accurate height prediction method that does not require bone age testing. Analyzes four inputs: child's age, height, weight, and average height of both parents.
Developed after studying thousands of children's growth patterns using linear regression analysis applied to population-level growth data. Because it includes current body measurements, it outperforms genetics-only formulas.
- Accuracy: ±2.1 inches for boys, ±1.7 inches for girls
- Best for children older than 4 years
- Most reliable non-clinical prediction available
Have your child's age, height, weight, and parents' heights ready?
Calculate with Khamis-Roche NowHeight Predictor Based on Parents (Mid-Parental Height Formula)
The Mid-Parental Height Formula is the simplest way to estimate a child's adult height using only the parents' heights. It requires no medical testing and works for any age, including babies and unborn children.
(Father + Mother + 5 in) ÷ 2(Father + Mother - 5 in) ÷ 2- Works for babies and young children when no current growth data is available
- Typical accuracy: within ±4 inches (10 cm) of final adult height
- Does not account for current growth trajectory. Use Khamis-Roche for children over 4
- Can also be used as a rough baby height calculator or for unborn children
Only have parents' heights? Use the Mid-Parental Height Formula calculator above.
Scroll to top and calculate nowBone Age Method (Wrist X-Ray)
Doctors use X-rays of the left wrist to assess growth plate maturity. Growth plates are thin cartilage bands. Their thickness reveals how much growth remains.
- Most accurate prediction method available
- Used only when doctors suspect growth disorders
- Evaluation methods: Greulich-Pyle, Tanner-Whitehouse
Bayley-Pinneau Method
Combines bone age data with height-for-age tables. Calculates the percentage of adult height already achieved to determine remaining growth potential. Requires bone age testing.
Roche-Wainer-Thissen Method
Uses bone age, current height, weight, and parental heights. Improves accuracy in some cases over Khamis-Roche but requires clinical bone age measurement. Primarily used in medical settings.
Can You Increase Height?
Your genes largely decide how tall you'll be. But how well you eat, sleep, and stay active during childhood can make a real difference in whether you reach that potential.
Nutrition
Adequate nutrition supports bone development. Key nutrients:
- Protein
- Calcium
- Vitamin D
- Zinc
Adequate Sleep
Growth hormone peaks during deep sleep.
- 9-11 hrs for school-age children
- 8-10 hrs for teenagers
Regular Exercise
Supports bone strength and overall development. Running, jumping, and sports encourage healthy bone growth.
Important: No exercise, supplement, or stretching program can increase height once growth plates close. Predictions are estimates. Genetics is the dominant factor.
How Accurate Is a Height Calculator?
This height predictor uses the Khamis-Roche growth model, trained on long-term studies of child growth data.
- Most predictions fall within 5-10 cm (2-4 inches) of final adult height
- Accuracy is highest when the child is older than 4 years
- Accurate height and weight measurements improve results significantly
- Correct parent height data is required for reliable output
- Results are a likely range, not an exact value
- Not suitable for children with known growth disorders
- Early or late puberty can reduce prediction accuracy
Frequently Asked Questions
Your adult height depends primarily on your parents' heights and your growth timing. Use the height calculator above. Enter your current age, height, weight, and your parents' heights to get a predicted height range based on the Khamis-Roche growth model. If you are already 18 or older, your growth plates have closed and your adult height is set.
Enter your son's age, current height, weight, and both parents' heights into the Khamis-Roche calculator above. Boys typically stop growing around age 18, though small increases may continue until 20. The Mid-Parental Height Formula can also give a rough estimate: (Father's height + Mother's height + 5 inches) ÷ 2.
The Khamis-Roche method (used in this calculator) is one of the most accurate non-clinical height predictors available. Typical accuracy is within ±2.1 inches for boys and ±1.7 inches for girls. Accuracy improves when the child is older than 4, measurements are precise, and parent heights are correct. Results are always a range, not a guaranteed value.
Yes. Parents' heights are the single strongest predictor of a child's adult height, accounting for 60–80% of height variation. The Mid-Parental Height Formula provides a rough estimate using only this data. However, combining parent heights with the child's current measurements (age, height, weight) through the Khamis-Roche model produces significantly more accurate results.
For babies and infants, use the Mid-Parental Height Formula calculator above. It requires only the mother's and father's heights. This gives a rough estimated height range. Note that accuracy is lower for babies than for older children, since current growth data is not factored in.
Use the growth chart section above to see the average height range by age for boys and girls. The 50th percentile represents the median height. Healthy children typically fall between the 3rd and 97th percentile. If your child is consistently above or below this range, discuss it with their pediatrician.
The most accurate method overall is bone age testing (wrist X-ray), used clinically by doctors. For non-clinical prediction, the Khamis-Roche method is the most accurate available. It uses age, height, weight, and parent heights, achieving ±2.1 inches accuracy for boys and ±1.7 inches for girls. This is the method used in the calculator on this page.
Scientific Bibliography & Data Sources
- Centers for Disease Control and Prevention. CDC Growth Charts.
https://www.cdc.gov/growthcharts - National Institutes of Health. Child Growth and Development Overview.
- Silventoinen K. Determinants of variation in adult body height. Journal of Biosocial Science.
https://pubmed.ncbi.nlm.nih.gov/12664962/ - World Health Organization. Child Growth Standards.
https://www.who.int/tools/child-growth-standards - National Sleep Foundation. Growth Hormone and Sleep in Children.
https://www.sleepfoundation.org/children-and-sleep - Khamis HJ, Roche AF. Predicting adult stature without using skeletal age. Pediatrics.
https://pubmed.ncbi.nlm.nih.gov/7936860/ - Tanner JM. Growth at Adolescence. Blackwell Scientific Publications.
- Greulich WW, Pyle SI. Radiographic Atlas of Skeletal Development of the Hand and Wrist.
- Tanner JM, Whitehouse RH. Assessment of Skeletal Maturity.
- Bayley N, Pinneau SR. Tables for predicting adult height from skeletal age.
- Roche AF, Wainer H, Thissen D. Predicting adult stature for individuals.