One Rep Max Calculator

Calculate your One Rep Max (1RM) to determine the maximum weight you can lift for a single repetition. Essential for programming your strength training effectively.

Enter Your Lift Details

For best accuracy, use 1-10 reps

What is 1RM?

One Rep Max (1RM) is the maximum amount of weight you can lift for a single repetition with proper form. It's a key metric for strength training, used to determine training loads and track progress over time.

About the Formulas

  • Epley: 1RM = weight × (1 + reps/30)
  • Brzycki: 1RM = weight × 36/(37 - reps)
  • Lombardi: 1RM = weight × reps^0.1

How to Use Your 1RM

Strength Training

Work at 85-95% of your 1RM for 1-5 reps to build maximum strength.

Muscle Building

Train at 70-85% of your 1RM for 6-12 reps for hypertrophy.

Endurance

Use 50-70% of your 1RM for 15+ reps to build muscular endurance.

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