Parents often wonder how tall their child will get as an adult. In order to answer this question, several height expectation methods have been developed. In general, it is well known that height is influenced both by environmental factors as well as genetic factors. The environment factors affect adult height by about 20~40%, whereas genetic factors by 60~80%. These stats show that especially the genetics inherited by parents are the most decisive factors in determining future height. Adult height can be more accurately estimated by diagnosing the bone age through an X-ray examination in a hospital. However, there are some more simple ways to predict a child’s height based on the heights of their parents.

**The Methods to Estimate Children’s Adult Height**

The methods to predict adult height are Greulich-Plye (GP), the Bayley-Pinneau method, and the TW3 method. BP (Bayley-Pinneau) method, which is most widely used in expecting the height, makes use of the current height and bone age to estimate the expected height. It was developed by Bayley and Pinneau in 1950 and revised in 1959. However, the BP(Bayley-Pinneau) method tends to overestimate adult height for CDGP (Constitutional Delay in Growth and Puberty). Recently new height prediction methods have been studied to correct the shortcomings of the BP (Bayley-Pinneau) method.

The most commonly used methods of measuring bone age are the Greulich-Pyle (GP) method and Tanner-Whitehouse 3 (TW3) method. The Greulich-Pyle (GP) method measures bone age by using photos of the left hand and wrist and compares them with a bone growth illustration book. This method is easy applicable without the help of a hospital. However, the method is only semi-quantitative because bone ages are illustrated by the year in the book. The Tanner-Whitehouse 3 (TW3) method also uses photos of the left wrist to measure bone age by summing up growth scores of each part of the bone. The method has been revised several times. TW3 nowadays applies RUS (radius-ulna-short bones) scores. This method is quite accurate to reflect bone growth but takes a long time to carry out.

Although those methods are scientifically investigated, there are reliability issues, because it is difficult for these types of height expectation methods to include changeable environment factors as well as genetic factors. In reality, there are significant differences in the predicted height results between the Greulich-Pyle (GP) method and Tanner-Whitehouse 3 (TW3) method. It is necessary to be cautious in carrying out those tests, rather than simply trusting the results.

Another height expectation method is the Khamis-Roche Method to predict adult height, without using bone age. The Khamis-Roche Method is looking at both parental height and the child’s height at the current age. Furthermore, it incorporates weight too as it is indicating that further growth will come. The accuracy and reliability of the Khamis-Roche Method are however low because it predicts adult height without bone age.**Height Calculators Give an Indication for Adult Height**

**Height Calculators Give an Indication for Adult Height**

The following ‘height calculators’ predict the adult height of children, by simply entering numbers. However, those calculators do not recognize the bone age determined by X-ray examination. Diagnosing the bone age by taking the X-ray in a hospital leads to more accurate results.

1. BoneXpert height calculator

https://bonexpert.com/ahp/#/Male/CauEurN/-/-/-/-/-

Adult Height Predictor of BoneXpert was created based on the BP (Bayley-Pinneau) method. Recently mathematics and data have been improved and parts of the new Tanner-Whitehouse method have been included. If you input your gender, race, bone age, height, etc, the height is predicted. Inputting the heights of the parents (optional) generates more accurate results.

- AHP(x-ray) is the prediction based on age, bone age and height.
- AHP(parental) is the prediction based solely on the parents’ heights.
- AHP(x+p) is the prediction based on age, bone age, height, and parental height.
- AHP(x+m) is the prediction based on age, bone age, height and height at menarche.
- A large discrepancy between AHP(x-ray) and AHP(parental) indicates that the child grows differently from what is expected from its parental heritage.

2. Tall.Life height calculator

https://tall.life/height-calculator-how-tall-will-i-be/

Tall.Life provides two types of height calculators. One of the height calculators is applying the Khamis-Roche method. Another is the most simple height calculator, which is based on the fact that children inherit their genes from both their parents. For a boy, 2.5 inches (6.5cm) are added to the average height of the parents and for a girl, 2.5 inches (6.5cm) are subtracted from the average height. The calculation is simple but not that accurate.

3. CDC Growth Charts

https://www.cdc.gov/GrowthCharts/

Even though this is not a height calculator, CDC Growth Chart of the USA can show children’s growth development over time. As a steady growth curve is constantly maintained in the chart, it can be useful to predict a child’s height. It includes the measurements on heights, weights, and head circumferences of children.

References:

- A New Model of Adult Height Prediction Validated in Boys with Constitutional Delay of Growth and Puberty (Reinehr T, Hoffmann E, Rothermel J, Lehrian T.J, Brämswig J, Binder G)
- Comparison of predicted adult heights measured by Bayley-Pinneau and Tanner-Whitehouse 3 methods in normal children, those with precocious puberty and with constitutional growth delay (Yeon Joung Oh, Byung Keun Yu, Jung Yeon Shin, Kee Hyoung Lee, Sang Hee Park, Kwang Chul Lee, Chang Sung Son)
- Predicting adult stature without using skeletal age: the Khamis-Roche method. (Khamis HJ, Roche AF)
- Adult Height Predictor, BoneXpert
- Height Calculator: How Tall Will I Be?, Tall.Life
- Growth Charts, Centers for Disease Control and Prevention