What is Duration Calculator?

Add, subtract and format time durations in seconds, minutes and hours.

Is Duration Calculator free to use?

Yes — Duration Calculator is free to use, with no sign-up, no install and no account.

No — Duration Calculator runs entirely in your browser, so your text, files and results never leave your device.

No — it works in any modern browser (Chrome, Edge, Firefox, Safari) with no downloads, accounts or plugins.

What is Duration Calculator?: Add, subtract and format time durations in seconds, minutes and hours.
Is Duration Calculator free to use?: Yes — Duration Calculator is free to use, with no sign-up, no install and no account.
Does Duration Calculator upload or store my data?: No — Duration Calculator runs entirely in your browser, so your text, files and results never leave your device.
Do I need to install anything to use Duration Calculator?: No — it works in any modern browser (Chrome, Edge, Firefox, Safari) with no downloads, accounts or plugins.