One Rep Max Calculator

    Estimate one-rep max from weight and reps with Epley, Brzycki, Lander, Lombardi and O'Conner formulas plus percentage targets.

    This calculator shows estimated 1RM (e1RM) when you enter a multi-rep set. If reps are 1, the entered weight is treated as the measured 1RM for that day.
    Estimated 1RM
    114.6 kg
    Range: 112.5 - 117.5 kg
    Input: 100 kg x 5 reps
    Epley
    116.7
    Brzycki
    112.5
    Lander
    113.7
    Lombardi
    117.5
    O'Conner
    112.5

    1RM intensity zones

    Marker: 80% = 91.7 kg
    EndEnduranceHypHypertrophyStrStrengthPeakPeak50%60%70%80%90%100%80%

    Percentage table

    Use it to choose working weights for programs such as 5x5, 3x3 or 8x8. Rounding step: 2.5 kg.

    % of 1RMWeight (kg)RepsUse
    100%1151Peak strength / test single
    95%1102Heavy strength work
    90%102.53-4Strength
    85%97.55-6Strength / hypertrophy
    80%92.57-8Hypertrophy
    75%859-10Hypertrophy
    70%8011-12Hypertrophy / endurance
    65%7513-15Strength endurance
    60%67.516-18Endurance and metabolic work
    50%57.520+Warm-up and technique

    Estimate one-rep max from a hard set

    English 1RM intent is usually e1RM: lifters enter a weight and reps performed, then use the result for training percentages rather than immediately testing a true max.

    w - weight lifted, r - reps performed.

    w - weight lifted, r - reps performed.

    Use e1RM cautiously

    • A 3-8 rep hard set usually estimates strength better than a high-rep endurance set.
    • Formula spread is normal; use the average and range as planning signals.
    • Do not attempt a true 1RM without warm-up, safeties, spotters and solid technique.

    Frequently Asked Questions

    Sources and References

    Calculations are based on the listed reference sources. Links open in a new tab.

    Updated:

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