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One Rep Max Calculator

Calculate your one rep max (1RM) using multiple proven formulas. Estimate your maximum lift based on weight and reps.

One Rep Max Results

Average 1RM 0
Formula 1RM

Training Percentages

Percentage Weight Training Goal

How to Use the One Rep Max Calculator

  1. Enter the weight you lifted (in kg or lbs).
  2. Enter the number of reps you completed with good form.
  3. Select your preferred unit (kg or lbs).
  4. Click "Calculate 1RM" to see your estimated one rep max.
  5. Review training percentages for different goals.

Frequently Asked Questions

What is one rep max (1RM)?

One rep max is the maximum weight you can lift for a single repetition of an exercise with proper form. It's a standard measure of strength used in training programs and progress tracking.

How accurate are 1RM calculators?

1RM calculators provide estimates, not exact values. Accuracy varies based on the exercise, experience level, and how close the test set is to failure. For beginners, estimates may be less accurate. Actual testing is more precise.

Why use different formulas?

Different formulas were developed using different populations and methodologies. Epley is popular for bodybuilding, Brzycki for general fitness. Comparing multiple formulas gives you a range to work with.

Should I actually test my 1RM?

Testing actual 1RM carries injury risk and requires proper warm-up and spotting. For most people, estimating from submaximal sets is safer. Only test 1RM if you're experienced and have proper supervision.

How do I use training percentages?

Training percentages help structure your workouts: 85-95% for strength, 70-85% for hypertrophy, 60-75% for endurance. Use your 1RM to calculate these percentages and plan your training accordingly.