Privacy

The short version: what you type stays in your browser.

The calculators run entirely on your device. Our pages tell your browser not to let them send data to any server (a security setting called Content-Security-Policy), so your numbers can't leave the page even by mistake.
Saving or sharing a result puts your numbers in the page address, after a "#". Browsers never send that part of an address to a website, so it doesn't reach us or our host. It does stay in your browser's history, and anyone you send the link to sees the numbers.
No ads, no cookies, no analytics scripts and no tracking.
Calendar reminders are files you add to your own calendar; we don't know who adds them.
No sign-up is needed for anything.
Our host, Cloudflare, keeps standard server logs (like any website) to keep the site running and secure.
Links to other sites don't tell them you came from here.