One-Rep Max Calculator

Estimate your one-rep max (1RM) for a lift from the weight and reps of a set, using the Epley and Brzycki formulas, plus training loads at common percentages. Runs in your browser.

Runs in your browser — your file never leaves your device

Frequently asked questions

Is One-Rep Max Calculator free to use?

Yes — One-Rep Max 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. One-Rep Max Calculator works on any modern browser — Windows, Mac, Linux, Android and iPhone.

How do I use One-Rep Max Calculator?

Open the tool, add your file (or paste your content), adjust any options, then press “Calculate 1RM”. Your result is ready to download in seconds.

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