Estimated One-Repetition Maximum
Estimate an approximate one-rep max from a submaximal set, using the Epley formula.
What this answers:
- Given a weight and rep count I actually lifted, what's an approximate one-rep-max estimate?
This is an illustrative estimate, not a validated maximum for any individual, and this tool does not instruct unsafe maximum-weight attempts. Supported for 1–10 reps in this version; accuracy varies by exercise and individual.
Estimated one-rep max
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How it's calculated
1RM = load × (1 + reps/30) for 2–10 reps; 1 rep returns the entered load unchanged.
Worked example
60 kg for 5 reps: 60 × (1 + 5/30) = 70 kg estimate.
Formula version: Epley (versioned, v1). Source: peer-reviewed literature on 1RM prediction equations and their limitations. Source last checked September 28, 2026.
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