Privacy policy

Summary: 123BMICalculator has no accounts, no advertising, no analytics and no cookies. The height, weight and other numbers you enter are sent to our server only to work out the answer. They are not stored in any database, and our server's access logs leave them out.

What reaches our server

  • The numbers you enter. The calculators work out the answer on our server, so what you type — a height, a weight, a waist measurement, an age — is sent there in the address of the request (for example /?ft=5&in=9&weight=165). It is used to calculate the result and to draw the result's picture, and then discarded. It is not saved or linked to you.
  • Ordinary web requests. Our server records the page address of each request without the part after the "?" that holds your numbers, together with the time, your IP address and your browser's user-agent, in standard logs used for security and troubleshooting. Referring addresses are not logged. Logs are rotated and deleted automatically.
  • Shared result links. When you share a result, your inputs travel in the link, so anyone who has it sees the same answer — and so does a social network that fetches its preview. Health details are personal: "Share result" puts your numbers in the link, and unticking "Include my result in the link" shares the plain calculator instead. Think twice before sharing someone else's numbers.

What stays on your device

  • Dark mode, if you switch it on, is remembered in your browser's local storage. Switching back to light removes it.
  • US or metric units: the last choice you made is remembered in local storage, so the calculators open in the units you use.

Neither is a cookie, neither leaves your device, and you can clear both by clearing this site's data in your browser.

What we don't do

  • No advertising, analytics or tracking scripts, and no third-party code on the page. Every script, style and image is served from our own domain.
  • No cookies.
  • No selling or sharing of data — we don't collect any to sell.

The share buttons are plain links. Nothing is sent to X, Facebook, WhatsApp, Telegram, Reddit or LinkedIn unless you click one, and from then on that service's own privacy policy applies. Links to sources such as the CDC or the WHO open their sites, which have their own policies.

Children

The site collects no personal information from anyone and needs no account, so it can be used by families, schools and clinics. A child's height, weight and age entered here are used only for the calculation.

Contact

Questions about privacy: hello@123bmicalculator.com.