One Rep Max (1RM) Calculator

Free one rep max calculator. Enter the weight you lifted and the number of reps to estimate your 1RM for bench press, squat, deadlift, and other exercises.

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Estimated 1RM (Epley) hesaplanacak
Estimated 1RM (Brzycki) hesaplanacak
Training Percentages hesaplanacak
50% / 60% / 70% / 80% / 90% hesaplanacak

What Is One Rep Max (1RM)?

One Rep Max (1RM) is the maximum amount of weight you can lift for a single repetition of an exercise. It is the gold standard for measuring absolute strength. Because testing true 1RM is fatiguing and carries injury risk, formulas exist to estimate it from submaximal lifts.

1RM Formulas

FormulaEquation
Epley (1985)1RM = w x (1 + r/30)
Brzycki1RM = w x (36 / (37 - r))
Lander1RM = (100 x w) / (101.3 - 2.67123 x r)
O'Conner1RM = w x (1 + 0.025 x r)

Where w = weight lifted, r = repetitions performed (2–10 reps for best accuracy).

Percentage Chart (% of 1RM)

% of 1RMReps (approx.)Training Goal
90–100%1–3Maximum strength
80–89%4–6Strength
70–79%7–10Strength-hypertrophy
60–69%11–15Hypertrophy (muscle growth)
Below 60%16+Muscular endurance

Tips for Estimating 1RM Safely

  • Use 3–6 reps for the most accurate estimates
  • Accuracy decreases above 10 reps
  • Perform the lift to true failure (with a spotter) for best data
  • Compare results across multiple formulas and average them

How to Use This Calculator

Using our calculator is simple: enter the required values into the input fields and click the calculate button. Results are displayed instantly on screen. You can adjust the values and recalculate to compare different scenarios and find the best option for your situation.

Frequently Asked Questions

QuestionAnswer
How accurate are the results?We use standard formulas and up-to-date 2025 rates. Individual circumstances may vary slightly.
Is this calculator free?Yes, completely free and no registration required.
What should I do for exact figures?For precise information, consult a relevant professional or official authority.
Does it work on mobile devices?Yes, it works seamlessly on all devices and screen sizes.

Important Notes

This calculator is provided for informational purposes only. For legal, financial, or medical decisions, always seek advice from qualified professionals. Calculation results do not constitute official documents. Legislative changes may affect results; please visit the relevant official website for the most up-to-date information. Our calculators are regularly updated to reflect current regulations and rates.

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Frequently Asked Questions

Maximal testing carries injury risk, especially for beginners. Estimating from a submaximal set (3-10 reps) is safer and accurate enough for programming.
65-75% for hypertrophy (8-12 reps), 80-85% for strength (4-6 reps), 85-95% for power (1-3 reps). Beginners should start lower.
The Brzycki formula is generally considered more accurate for lower rep ranges (1-10). Epley tends to overestimate at higher rep counts.