One Rep Max Calculator
Estimate your 1RM from any set using proven formulas.
Estimated one-rep max
115 kg
Epley
117 kg
Brzycki
113 kg
85% (5-rep work)
97 kg
70% (10-rep work)
80 kg
Estimating without maxing
1RM formulas extrapolate from a submaximal set: Epley adds 1/30 of the load per rep; Brzycki divides by a shrinking denominator. Both are accurate within a few percent under 10 reps, and this calculator averages them. Testing a true max isn't necessary for programming.
Using percentages
Programs prescribe work as %1RM: strength lives at 80–90% for 3–6 reps, hypertrophy at 65–80% for 6–12. Recalculate every few weeks — the estimate is a moving target when training works.
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