Free fitness calculator

1RM Calculator

Estimate one-rep max and training loads from working weight and reps.

Best from 2–10 reps. High-rep estimates are less reliable.

What is one-rep max?

One-rep max is the estimated heaviest weight you could lift for one clean rep.

Train smarter

Use the estimate for programming loads, not as an excuse to max out constantly.

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Search queries this calculator helps answer

This page is written for people looking for quick calculator-style answers, including these common search phrases:

How to use the result

Use the calculator output as a starting estimate. Check the assumptions, compare it to real-world results, and adjust if your situation changes.