One-Rep Max Calculator
Estimate your one-rep maximum for any lift using the Epley formula. Enter a weight you can lift for multiple reps, and we will project your 1RM and recommended working weights.
How the Epley Formula Works
The Epley formula estimates your one-rep max as: 1RM = weight x (1 + reps / 30). This is one of the most commonly used formulas in strength training and provides a reliable estimate for most lifters up to about 10 reps. Beyond 10 reps, the estimate becomes less accurate as muscular endurance plays a larger role than raw strength.
Tips for Accurate Results
- Use a weight you can perform with good form for all reps
- Test with a rep range of 3-10 for the most accurate estimate
- Warm up properly before testing
- Use the same formula consistently to track progress over time
Related Tools: Track your strength progress over time with our Measurement Log and see visual changes with Progress Photos.