Privacy policy

The calculators

Every calculation on this site happens in your browser. The values you type are not transmitted to us, not logged, and not stored. Closing the tab discards them. Your theme and unit preferences are kept in your browser's own local storage so the site looks the same next visit; that never leaves your device and we cannot read it.

The bug-report form

If you send a correction or bug report, we store what you submitted: the message, the page it came from, the tool it concerns, your email address if you chose to give one, your browser's user-agent string, and a salted one-way hash of your IP address. The hash exists only to rate limit abuse - it cannot be reversed into an address, and we never store the address itself. An email is optional and is used solely to reply to you.

The form is protected by Cloudflare Turnstile, which checks that a submission comes from a person rather than a script. Turnstile is operated by Cloudflare and receives your IP address as part of that check.

Hosting

The site is served by Cloudflare Pages. Like any web host, Cloudflare processes the requests needed to deliver the page and keeps its own aggregate request logs for security and reliability. We do not attach any visitor identifier to those counts and cannot identify a person from them.

Advertising

This site shows ads served by Google AdSense. Google and its partners use cookies and similar identifiers to serve ads, to limit how often you see the same one, and to detect fraud. That applies even to non-personalised ads, which still use cookies for frequency capping and reporting. Ads are the only thing on this site that stores anything on your device beyond your own display preferences.

If you are in the European Economic Area, the United Kingdom or Switzerland you will be asked for consent before any advertising cookie is set, and you can change or withdraw that choice at any time through the same consent dialog.

You can opt out of personalised advertising across the web at Google My Ad Center, review how Google uses data from sites that use its services at Google's partner-sites page, and manage third-party vendors at optout.aboutads.info.

What this site does not do

There is no analytics script on this site. We do not build a profile of you, do not sell or share data, and run no tracking beyond what the advertising above requires. There is no newsletter, no account, and nothing to sign up for.

Your rights and how to reach us

You can ask what we hold about you, ask for it to be corrected, or ask for it to be deleted. In practice the only thing we are likely to hold is a bug report you sent us, and we will delete it on request. Use the Report a bug link in the footer to reach us.

Last updated 2026-08-29.