Terms of Use

Last updated 2 October 2026. These terms cover your use of howtallai.com ("howtallai", "we", "us"). By using the site you agree to them. They are short and written in plain English; if anything is unclear, ask us via the contact page.

What the site is

howtallai is a free height predictor for parents and teenagers, plus height and weight percentile charts and reference pages on growth. There is no account and no paid tier. How we handle data is described in the Privacy Policy, which forms part of these terms.

For information and education only

• It is not medical advice. Nothing on the site is medical advice, diagnosis or treatment, and it does not replace a qualified health professional.
• Results are estimates. The predicted height is calculated from published methods (mid-parental height and current-height projection). It has not been validated against a clinical dataset, and an individual's adult height can differ from it.
• See a doctor about real concerns. If you are worried about a child's growth, puberty or health, speak to a paediatrician or family doctor. Do not delay or skip medical care because of a result on this site.

CDC and WHO data

The percentile charts use growth reference data that the U.S. Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO) publish openly. howtallai is not affiliated with, endorsed by or sponsored by the CDC or the WHO, and their names appear only to identify the source of the data.

Who can use the site

The calculator and charts are for parents, carers and teenagers. A child under 13 should use the site with a parent or guardian. The optional email field is for parents and for teens 13 or older; if you are under 16, ask a parent first. It is not shown when a teen enters an age under 13, and children under 13 should not submit an email address. This matches our Privacy Policy.

Acceptable use

Please use the site normally. You agree not to:

• Submit email addresses that are not yours, submit the form repeatedly or automatically, or otherwise misuse the email form.
• Scrape or copy the site in bulk with automated tools. Search engines indexing the site in line with robots.txt are fine.
• Interfere with the service: overloading it, probing it for security weaknesses, getting around abuse limits, or uploading malicious code.
• Use the site for anything unlawful.

We may block access or delete submissions that break these rules.

Content and intellectual property

The text, design and code of howtallai belong to us unless stated otherwise. You are welcome to use your own results however you like, to link to any page, and to quote short excerpts with a link back. Please do not republish whole pages or reuse the site's content commercially without asking first. CDC and WHO data remain subject to their publishers' own terms.

Links to other sites

Some pages link to other websites, such as public health sources or Google's analytics opt-out add-on. We do not control those sites and are not responsible for their content or how they handle your data.

No warranty

The site is free and provided "as is" and "as available". We try to keep it accurate and working, but we do not promise that results, charts or content are correct, complete or suitable for any particular purpose, or that the site will always be available. We may change, pause or remove any part of it at any time.

Limitation of liability

To the extent the law allows, howtallai is not liable for any loss or damage arising from your use of the site or your reliance on its results or content, including decisions about a child's health, care or treatment. Some places do not allow certain limits on liability; where that applies, our liability is limited only as far as the law permits.

Changes to these terms

We may update these terms as the site changes. When we do, the date at the top of this page will be revised. Continuing to use the site after an update means you accept the new version.

Contact

Questions about these terms can be sent via the contact page.

howtallai.com provides statistical estimates for general information only. It is not medical advice, diagnosis or treatment.