About CalcWhen

CalcWhen is a small, independent drawer of everyday tools, built and maintained by the CalcWhen team. It exists for the questions that are too small for an app and too annoying to work out by hand: how many days until, how long does this take to read aloud, what week number is it, is this password actually strong.

Every tool states the method it uses — the ISO week rule, the typing-test convention of five characters per word, the checksum inside every barcode — and works an example in plain sight. Tools run entirely in your browser; the password you generate and the text you paste are never sent anywhere, because there is nowhere for them to go.

The site is supported by advertising, which is also why it stays free and needs no accounts.

Corrections are welcome. If a rule, a constant, or an explanation looks wrong, tell us at [email protected] and we will check it against the source and fix it in the open.