100 × 5
Epley 116.7, Brzycki 112.5 and Lombardi 117.5 average to an estimated 1RM of about 115.5.
One-Rep Max Calculator
Estimate your one-rep max from a set of reps with the Epley, Brzycki and Lombardi formulas, plus training loads.
Result
Enter your values and select Calculate to see the result.
Runs in your browser — nothing you enter is sent to a server.
How the One-Rep Max Calculator works
Enter a weight you lifted and how many clean reps you did. Three common formulas estimate the most you could lift once, and the calculator shows their average plus training loads from 60% to 100% of that maximum. Estimates are most reliable from sets of 10 reps or fewer.
Formulas
Epley
1RM = weight × (1 + reps ÷ 30)
Brzycki
1RM = weight × 36 ÷ (37 − reps)
Lombardi
1RM = weight × reps0.10
Examples
Training at 80%
With a 115.5 max, 80% is about 92.4 — usually good for around 8 reps.
Frequently asked questions
Is it safer than testing a true max?
Yes. Estimating from a heavy set avoids a maximal attempt, which is harder on joints and needs a spotter.
Why do the formulas differ?
They were fitted to different lifters and lifts. They agree closely at low reps and drift apart above 10.
Kilograms or pounds?
Either — the result is in the same unit you enter.
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