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One rep max calculator.

Estimate one-repetition maximum from a submaximal set in kilograms or pounds using Epley and Brzycki equations.

1RM calculatorone rep max calculatorestimated 1RM

DIRECT ANSWER

A one rep max calculator estimates the heaviest single repetition from a lighter set. Enter a load and 1–12 completed repetitions to compare Epley and Brzycki estimates; the result is an estimate, not a tested maximum.

CALCULATOR

Estimate your 1RM

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Weight liftedCompleted reps

Unitkglb

Combined estimate100.3 kg

Epley101.3 kg

Brzycki99.3 kg

95%95.3 kg90%90.3 kg85%85.3 kg80%80.3 kg75%75.2 kg70%70.2 kg65%65.2 kg60%60.2 kg

How the estimate works

Epley uses load × (1 + reps ÷ 30). Brzycki uses load × 36 ÷ (37 − reps). Both are mathematical estimates and can diverge from a true maximum because exercise, technique, effort and the athlete all matter.

Use the same lift

Compare estimates from the same exercise and similar execution. A machine press estimate should not be treated as a barbell bench-press maximum.