1RM
One Rep Max Calculator
The most you could lift once, estimated from a set of several reps, with a percentage table.
Result…
How it's calculated
Epley (1985): 1RM = weight × (1 + reps ÷ 30) Brzycki (1993): 1RM = weight × 36 ÷ (37 − reps)
Lifting a true one-rep maximum is risky and tiring, so most lifters estimate it from a harder set of 3–10 reps. The two formulas agree near 10 reps and differ a little at low reps; both lose accuracy past about 10. Use the percentage table to plan sets, and lift with a spotter.
Your numbers, step by step
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