One-rep max (1RM) calculator
Enter the weight you lifted and how many reps you completed. We'll estimate your one-rep max as the average of the Epley and Brzycki formulas.
Use a set between 1 and 12 reps for the most accurate estimate.
How the 1RM calculator works
The Epley formula estimates one-rep max as weight × (1 + reps / 30). The Brzycki formula uses weight × 36 / (37 − reps). Both are accurate inside the 1–12 rep range and start to drift on higher-rep sets, which is why we cap input there.
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