Contact & About

howtallai is a free height prediction tool with a set of reference pages on childhood and adolescent growth. There is no app to install, no account, and no paid tier — the prediction and its range are shown in full to everyone.

Get in touch

Email: [email protected]

Corrections to anything on the site are especially welcome — if something here is wrong or out of date, please say so and cite what it should be.

Use the same address for privacy requests, including asking what data is held about you or requesting deletion. See the privacy policy for what is stored.

How the prediction is calculated

The calculator combines two independent estimates rather than relying on either alone:

Mid-parental height — the family genetic midpoint, derived from both parents' heights with a sex adjustment. This is the standard first-line method used in paediatric practice.
Current-height projection — extrapolating the child's own measured height forward using the typical fraction of adult height reached at their age and sex.

The two are blended, adjusted for reported pubertal stage, and reported as an interval whose width varies with the child's age, how complete the inputs are, and how much the two methods disagree. Every result page states which method was used, which inputs it drew on, and the applicable age range. There is a fuller explanation on the mid-parental height page.

Known limitations

Stated plainly, because most sites in this category do not:

It is a statistical estimate, not a measurement. Two siblings with identical parents can finish eight to ten centimetres apart, and no method built on parental heights can distinguish between them in advance.
It has not been validated against a clinical dataset. We have not benchmarked this calculator against measured adult outcomes, so we make no claim to be more accurate than any other tool.
It is designed for roughly ages 8 to 20. Outside that range the assumptions behind both methods break down.
It cannot detect a medical cause of poor growth. Only a clinician examining the child can do that, which is why several pages here point toward a doctor rather than toward the calculator.
Self-reported inputs limit it. Remembered parental heights and doorframe measurements both carry error that flows straight into the result.

Editorial approach

The reference pages draw on standard paediatric growth material — mid-parental and target range methodology, WHO and CDC growth reference practice, and the established literature on pubertal timing and growth plate closure. Where evidence is weak or contested, the pages say so rather than rounding it into confidence.

The site takes a deliberate position against the "grow taller" product category. Nothing sold as a supplement, stretch, device or routine lengthens bone, and several pages here say so directly. We do not sell any such product and do not accept affiliate arrangements with anyone who does.

Medical disclaimer

Nothing on this site is medical advice, diagnosis or treatment, and it is not a substitute for consulting a qualified health professional. Growth estimates are statistical projections about populations applied to an individual, which is inherently imprecise. If you have any concern about a child's growth, pubertal development or health, speak to a paediatrician or family doctor.