Privacy policy

Last updated 2026-09-02

The short version

The numbers you type into the calculators never leave your browser. They are not sent to a server, not stored, and not logged. The calculation runs entirely in JavaScript on your own device.

What we do not collect

When you use the "Share link" button, your inputs are encoded into the page URL so the link reproduces your calculation. That URL is created in your browser and is only shared if you choose to share it. Note that anyone you send it to will see the figures it contains.

Server logs

This site is served by a standard web server, which records ordinary request information: the page requested, the time, the browser's user agent, the referring page and a truncated IP address. These logs are used to keep the site running and to detect abuse. They are not used to build a profile of you and are retained only briefly.

Cookies

This site currently sets no cookies of its own and no advertising cookies. If that changes, this policy will be updated before any cookie is set and a notice will appear on the site.

Advertising

This site is supported by display advertising. When advertising is active, third-party vendors including Google may use cookies to serve ads based on your prior visits to this and other websites.

Analytics

We may use a privacy-respecting analytics tool to count page views and see which pages are useful. Where analytics are in use, they are configured without cross-site tracking and without cookies that identify you personally.

Your rights

Because we do not collect personal data through the calculators, there is generally nothing held about you to access, correct or delete. If you are in the EEA, the UK or California and believe we hold information about you, write to [email protected] and we will respond.

California residents: we do not sell or share personal information as those terms are defined by the CCPA/CPRA. Advertising vendors may process identifiers as described above; the opt-out links in the advertising section apply.

Children

This site is not directed at children under 13 and we do not knowingly collect information from them.

Changes

If this policy changes, the date at the top of this page changes with it. Material changes — such as the introduction of advertising cookies — will be signposted on the site.

Contact

Questions about this policy: [email protected].