Privacy policy

Last updated 24 August 2026. The short version: the calculators run entirely in your browser and nothing you type into them ever leaves your device.

What the calculators do with your data

Nothing. Every calculator on this site — CSS, pace, course conversion, SWOLF — calculates in JavaScript inside your own browser. Your times, distances and stroke counts are never transmitted to us, never stored, and never logged. Close the tab and they are gone.

Anonymous usage events are recorded — for example, that a CSS calculation happened — so we can tell which tools are worth improving. Those events do not carry the values you entered.

What we collect

• Analytics. We use Google Analytics 4 and Cloudflare Web Analytics to count visits and see which pages are read. This covers pages viewed, approximate location at country level, device type, referring site and time on page. Cloudflare Web Analytics is cookie-free by design.
• Advertising. Google and its partners serve the ads on this site and may set cookies or read device identifiers to select and measure them.
• Server logs. Standard web server records including IP address, kept briefly for security and diagnostics.

We do not run a newsletter, do not ask for an account, and do not sell or share data with anyone beyond the providers named above.

Cookies and advertising

Third-party vendors, including Google, use cookies to serve ads based on your prior visits to this and other websites. Google’s use of advertising cookies enables it and its partners to serve ads based on your visit to this site and other sites on the internet.

You can opt out of personalised advertising at Google Ads Settings, or opt out of third-party vendors’ use of cookies for personalised advertising at aboutads.info. Blocking cookies in your browser also works and does not break anything on this site.

Your rights

If you are in the EU, the UK or another jurisdiction with equivalent data protection rules, you have the right to request access to any personal data we hold about you, to have it corrected or erased, and to object to its processing. Write to [email protected] and we will respond within 30 days.

For data held by Google, use Google’s privacy controls directly — we cannot delete data from their systems on your behalf.

Children

This site is written for adults and is not directed at children under 13. We do not knowingly collect personal information from children.

Changes

If this policy changes materially, the date at the top changes with it. Related: terms of use and our editorial policy.