Free tool
Estimate your 1RM from any weight and rep range, plus ready-to-use 80% and 65% training targets.
Epley formula. Most accurate under 10 reps — treat anything above that as a rough estimate.
How this works
This uses the Epley formula — 1RM = weight × (1 + reps ÷ 30) — one of the most widely used estimates in strength training. It's most accurate under 10 reps; above that, fatigue and technique breakdown make any estimate rougher.
The two percentage columns are practical training targets: 80% of your 1RM is a common range for pure strength work (low reps, higher intensity), while 65% sits in a better range for volume and hypertrophy work without grinding every set.
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