GCD & LCM Calculator

Find the GCD (HCF) and LCM of any list of whole numbers. Runs in your browser.

Runs in your browser — your file never leaves your device

Frequently asked questions

Is GCD & LCM Calculator free to use?

Yes — GCD & LCM Calculator is completely free with no limits, no watermarks and no sign-up. It runs in your browser, so there is nothing to pay for.

Are my files uploaded or stored anywhere?

No. This tool does all its work locally in your browser using your own device's power. Your files never leave your device and we never see them.

Do I need to install anything or create an account?

No installation and no account needed. GCD & LCM Calculator works on any modern browser — Windows, Mac, Linux, Android and iPhone.

How do I use GCD & LCM Calculator?

Open the tool, add your file (or paste your content), adjust any options, then press “Calculate”. Your result is ready to download in seconds.

Is it prime? If not, see its factors.

nCr and nPr, exact — even huge numbers.

Area, angles & type from three sides.

Find the missing side of a right triangle.

Read a cookie header.

12 headline ideas for any topic.