Last updated: September 2026.
What we collect
The calculators run entirely in your browser. The values you type are never sent to our servers or to anyone else, and they are not stored when you leave the page.
When you load a page, our hosting provider, Cloudflare, processes the standard information any web request carries (your IP address, browser type, the page requested, and the time). Cloudflare uses this to deliver the site and protect it from abuse. We see this only as aggregate traffic figures.
Cookies and analytics
This site uses Google Analytics to count visits and see which pages are used. Analytics sets cookies and records your IP address, browser and the pages you open. We use it only as aggregate traffic figures; we never try to identify anyone from it, and we do not upload anything you type into the tools. You can opt out of Google Analytics on every site you visit with Google's opt-out add-on.
Advertising
This site carries, or will shortly carry, advertising from Google AdSense, which is how it is paid for.
- Google, as a third-party vendor, uses cookies to serve ads on this site.
- Google's use of advertising cookies enables it and its partners to serve ads to you based on your visit to this site and other sites on the internet.
- You can opt out of personalised advertising in Google Ads Settings, or opt out of a third-party vendor's use of cookies for personalised advertising at aboutads.info.
- If you are in the European Economic Area, the United Kingdom or Switzerland, you will be asked for consent before personalised ads are shown, and you can change or withdraw that choice at any time from the consent link on the page.
Advertisers do not receive anything you type into the tools on this site: the calculations happen in your browser and are never sent to us or to anyone else.
What we do not do
We do not sell personal data, we do not run email marketing, and we have no login, so there is no account or profile of you here.
Links to other sites
Pages may link to other websites. Their privacy practices are their own.
Children
The site is usable by students of any age. Because nothing is collected, there is nothing to collect from children either.
Your rights
If you are in the EU, UK, California or another place with data-protection rights, you can ask what we hold about you. The answer today is nothing, but you are welcome to ask through the contact page.
Changes
Changes to this policy appear on this page with a new date at the top.