1RM Estimator
Enter a weight you lifted and the reps you moved it for. The estimator calculates an estimated one-rep max (e1RM) from the Epley and Brzycki formulas, averaged for a balanced estimate — then shows the rep-max curve and your working percentages.
Enter a weight and reps to estimate your one-rep max.
Rep-Max Curve
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Working Weights
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Rep capacity at a given percentage varies by athlete and exercise.
Approximate reps are display guidance only — not program prescription.
Enter valid inputs to create a result link.
How the estimate works
Two well-established formulas each estimate a one-rep max from a multi-rep set. Averaging them balances Epley's slight optimism with Brzycki's conservatism.
Epley: 1RM = weight × (1 + reps / 30)
Brzycki: 1RM = weight × 36 / (37 − reps)
The displayed estimate is the average of the two formulas, carried at full precision and rounded only for display.
For a single rep (reps = 1), the estimate is the weight you entered. A performed single is not inflated through the formulas.
Tested 1RM
A maximal single actually performed — a true maximum lifted on the day.
Estimated 1RM
A calculated estimate (e1RM) derived from a multi-rep set, not a tested maximum.
Put the estimate to work.
Many AthleticPeak Pro Programs use a one-rep max or Training Max to calculate working weights and progression. Once you have an estimate, explore the Programs that match the way you want to train.
Representative percentage-driven programs: