Privacy

The short version: your calculator inputs never leave your browser, and we don't build a profile of you. Oddly Useful is a static website with no backend, no database and no user accounts.

Your calculations stay on your device. Every result is computed in your browser from the numbers you type. Those numbers are never sent to us or to any analytics service. When you share a result, your inputs are encoded into the link itself — so only the person you send it to can see them.

Analytics. To understand roughly how many people use the site and which calculators are popular, we use two privacy-respecting tools:

• Google Analytics 4, which sets first-party cookies and collects anonymised usage data such as the pages viewed, rough device type and country. We send it only the page path and simple events like "a calculator was used" or "a result was shared" — identified by the calculator's name, never the values you entered.
• Cloudflare Web Analytics, which is cookieless and collects only aggregate, anonymised traffic data.

Our host, Cloudflare, may also keep standard, anonymised server logs for security and reliability, as almost every website does.

The results here are for curiosity and entertainment. They rely on simplifying assumptions and are not medical, financial or life-expectancy advice.