Estimate your one-rep max using the Epley formula
About the Epley Formula
The Epley formula (1RM = weight x (1 + reps/30)) is one of the most widely used equations for estimating one-rep max. It works best for rep ranges between 2-10. For best results, use a weight you can lift for 3-8 reps with good form.
How it works
Estimates the heaviest weight you could lift once, from a set taken close to failure at a lighter weight. Used to set training percentages without the injury risk of a true max attempt.
Epley: 1RM = w × (1 + r/30) | Brzycki: 1RM = w × 36 / (37 − r)
wweight liftedrrepetitions completed
- Epley: 100 × (1 + 5/30) = 100 × 1.1667
- Brzycki: 100 × 36/(37−5) = 112.5
- Accuracy degrades above about 10 reps, since the formulas assume a set taken near failure.
- Estimates run high for deadlifts and low for bench press relative to true tested maxes.
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One Rep Max is built on published formulas and reference ranges from established health sources. We revisit it periodically as guidance evolves; the "Last reviewed" date above shows when that last happened. If something looks wrong, tell us with the feedback button in the bottom-right corner.