Privacy policy
Last updated 26 September 2026. The calculators on this site run in your browser, and what you type into them is never sent to a server.
Calculator inputs
All calculations are done by JavaScript on the page, in your browser. Your inputs are not submitted to a server, and we don't store them.
Share links and URL parameters
The calculators never write what you type into the page address. A link containing your values is created only when you press "Copy share link" (for example ?down=300&up=20), so you can bookmark or send a result. Like any web address, a shared URL is kept in browser history, is seen by anyone you send it to, and, when it is opened, is recorded together with its parameters in the hosting provider's access logs and in the cookieless page statistics described below. The parameters contain only calculator values such as numbers and units.
Copy buttons
Copy buttons write text to your clipboard only when you press them. Nothing is read from your clipboard.
Theme preference
If you choose a light or dark theme, the choice is saved in your browser's localStorage under the key theme, so the site remembers it on your next visit. It stays on your device and is not sent to us. The site itself sets no cookies by default. Details are on the cookies page.
Analytics and advertising (only with your consent)
The site owner can enable Google Analytics 4 to understand which tools are used, and a display-ad provider such as Google AdSense to fund the site. Neither loads unless you accept in the consent bar. If you decline, or ignore the bar, they do not load.
When analytics is enabled and accepted, the events we send never include the numbers you type. They contain only event names (such as calculator_used, copy_result and language_changed), the tool id, the units selected and the page language. Google Analytics also receives page addresses without their query string, so values in a shared link are not sent to Google. Google Analytics also collects standard information such as approximate location, device and browser type, and may set cookies, as described in Google's own policies.
When ads are enabled and accepted, the ad provider may use cookies or similar technologies to show and measure ads, under its own privacy policy. See how Google uses information from sites that use its services.
Hosting logs
Like most websites, the hosting provider keeps standard access logs, which typically include your IP address, the page requested (with any URL parameters), the time, the referring page and your browser's user agent. These are used to run and protect the service.
Cloudflare Web Analytics (cookieless)
The site is hosted on Cloudflare, which runs Cloudflare Web Analytics on every page for every visitor. A small script from static.cloudflareinsights.com reports aggregate page statistics: the page address, the referring page, browser and device type, approximate country, and page-load performance measurements. According to Cloudflare, it sets no cookies, stores nothing in your browser to recognise you, and does not fingerprint visitors, which is why it runs without the consent bar.
It never receives the values you type into a calculator, because those are not in the page address unless you open a share link. You can block it with most content blockers without affecting the calculators. See Cloudflare Web Analytics and Cloudflare's privacy policy.
If you email us, we receive your email address and message and use them only to reply and to fix what you report.
Your choices
- You can use every calculator without accepting analytics or ads.
- You can change your consent choice later by clearing this site's data in your browser, which brings the consent bar back.
- You can clear the saved theme the same way, or block storage for the site in your browser settings.
- For data held by Google Analytics or an ad provider, use the controls those providers offer.
Depending on where you live, you may have legal rights to access or delete personal data; contact us and we will help with anything we hold, which is normally only email correspondence.
Changes and contact
If what the site collects changes, this page will be updated before or when that happens, along with the date above. Questions about privacy: see the contact page. The rules for using the site are in the terms of use.