How tall will I be? How tall will my child be? These are important questions as so many aspects of our lives are impacted by our height. That is why Tall.Life has assembled the below height calculators for you. The first is more accurate but only works for ages four and up. But even this calculator is merely an approximation, so don’t start planning for the NBA draft based on it. Below these is an explanation of how height calculators work. If you want to ask a question in the comments, please make sure to mention which calculator you used and what numbers you entered.
By receiving a combination of genes from both parents, a child will tend to have a height somewhere between their parents’ heights, a bit more for girls and a bit less for boys. This leads to the simplest method of estimating adult height: take the average height of the parents and add 2.5 inches (6.5cm) for boys or subtract 2.5 inches for girls. This is the method used by the second of the above height calculators. But if the child’s height trajectory points to a greater height, don’t go hunting down the mailman just yet; with so many genes involved, some of which may be recessive, and the possibility of environmental influences, child height can differ considerably from parental height.
Another popular approach to predicting adult height is to double a boy’s height at age 2 or a girl’s height at age 18 months. While this approach does incorporate the child’s own height, and thus they’re own genetics, it is over simplified and unlikely to provide an accurate prediction.
The Khamis-Roche Method  combines the best of both of these methods by looking at both parental height and the child’s height at the current age. Furthermore, it incorporates weight as this too is telling of growth to come. This is the method used by the first height calculator at the beginning of this article.
More advanced height calculators make use of bone age, which is a measure of age based on the size and shape of the bones as seen in radiographs, and formulas such as those found in the Tanner-Whitehouse method. Bone age isn’t always available, and it was actually for this reason that the Khamis-Roche method was developed.
Another method is to calculate height percentile and then check that same height percentile for adults. Similarly, there are also growth charts for analyzing height, but that’s a topic for another article.
While a height calculator may be useful, it is not intended for cases where an underlying height related disorder or syndrome may be present. Additionally, these methods have generally been developed for white American children and thus some prediction accuracy may be lost for other populations. In actuality, a pediatrician or endocrinologist is the best resource when it comes to understanding a child’s height.