One Rep Max (1RM) Calculator
Estimate the maximum weight you can lift for a single repetition based on your current performance. Perfect for strength training and program design.
Calculate Your One Rep Max
Enter 1-10 reps for accurate results
Estimation Methods
Epley Formula
Most common method for estimating 1RM. Best for 1-10 reps.
Where w = weight lifted, r = repetitions
Brzycki Formula
Popular in powerlifting. More conservative estimate.
Accurate for lower rep ranges (under 6 reps)
Lombardi Formula
Good for higher repetition sets.
Uses exponential relationship between reps and weight
O’Conner Formula
Simple calculation that provides a reasonable estimate.
Less aggressive than Epley formula
Understanding One Rep Max
Your one-repetition maximum (1RM) is the maximum amount of weight you can lift for a single repetition of a given exercise. This metric is crucial for:
- Designing effective strength training programs
- Tracking progress in weightlifting
- Setting appropriate training weights
- Periodizing your workouts
- Establishing baselines for different exercises
How to Use This Calculator
For the most accurate estimate:
- Perform an exercise with a weight you can lift 1-10 times with proper form
- Enter the weight you lifted
- Enter how many repetitions you completed
- Select the exercise type for specific adjustments
- Get your estimated 1RM and use it to plan your training
Common Exercises for 1RM Testing
Safety Considerations
While 1RM testing is valuable, it carries risks:
- Always warm up properly before attempting heavy lifts
- Use spotters for exercises like bench press and squat
- Consider submaximal testing instead of actual 1RM attempts
- Never test your 1RM without proper training experience
- Listen to your body and stop if you feel pain