Privacy Policy

Last reviewed in January 2026. Written to be read rather than skipped.

The short version

Everything you type into the calculator is processed inside your own browser and is never sent to us or to anyone else. We operate no database of user readings because no readings ever reach us.

What happens to the values you enter

Percentages, glucose figures, dates, notes, names and targets all live in the memory of the tab you have open. They power the conversion, the chart and the report, and they are discarded when you close that tab.

One optional control changes this. If you tick the box marked to remember entries on this device, the tool writes them into your browser local storage so they survive a refresh. That copy sits on your machine only. It is never uploaded, and it is never readable by us. Untick the box, or use delete saved data, and the copy is removed immediately.

Because storage is on the device rather than an account, anyone with access to that browser profile could open the tool and see saved entries. Leave the option switched off on shared or public computers.

Cookies

We set no cookies. There is no session, no login, and no identifier following you between visits or between pages.

Analytics and tracking

This site runs no analytics platform, no advertising network, no tag manager, no heat mapping, and no social tracking pixels. We do not build profiles of visitors and we have nothing to sell to anyone who would want one.

Server logs

If you reach this site over the internet, the hosting provider serving the files may keep standard access logs containing an address, a timestamp, and which file was requested. That is ordinary infrastructure record keeping, it is common to essentially all web hosting, and it never contains anything you typed into the calculator. Those logs are retained by the provider under their own policy.

Third party requests

The site is deliberately close to self contained. Two exceptions exist and both are worth stating plainly.

  • Web fonts. The Poppins typeface is requested from Google Fonts, which means your browser contacts that service when the page loads. If it is unavailable, the site falls back to a font already on your device and everything still works.
  • PDF libraries. Pressing the PDF download button loads two open source libraries from a public code delivery network on first use. They run inside your browser and receive no data from us. Nothing about your readings is transmitted during that request.

Every other part of the site loads from the same place the page came from.

Email you send us

If you write to us, we receive your message and your address, and we keep both only as long as needed to reply and to track any issue you reported. We ask you not to include personal health information, and we delete it if it arrives anyway.

Children

The tool is intended for a general adult audience. We knowingly collect nothing from anyone, of any age, because we collect nothing at all.

Your control

Because we hold no record of you, there is no account to close and no data of yours for us to export or erase. Control sits entirely with you.

  • Clear saved entries with the delete saved data button inside the tool.
  • Clear site data through your browser settings at any time.
  • Use a private window if you want nothing written to the device at all.

Changes to this policy

If the way the site handles information ever changes, this page changes with it and the review date above is updated. Any change that affects your information will be described here rather than hidden in a summary.

Questions

Anything unclear is worth asking about. Reach us through the contact page.