One Rep Max (1RM) Calculator
Safely calculate your theoretical One Rep Max for squats, bench press, and deadlifts. Use trusted formulas (Epley, Brzycki) to determine your strength limits without risking injury.
Safe Strength Tracking
Testing your true 1-Rep Max in the gym is physically taxing and highly dangerous without a spotter. This tool uses scientifically validated sports-science formulas to estimate your maximum lifting capacity based on the weight and reps you can already perform comfortably. It also provides a percentage breakdown chart for your training programs.
Why Use Our One Rep Max Calculator?
- Prevent Injury: Find your max without actually lifting dangerous weights.
- Training Percentages: Instantly generates 50% to 95% working sets for programs like 5/3/1.
- Multiple Formulas: Averages out Epley and Brzycki equations for higher accuracy.
- 100% Private: Your fitness data stays on your device.
How to Use the One Rep Max Calculator
Enter the amount of weight you lifted.
Enter the number of repetitions you completed (ideally between 2 and 10).
Click 'Calculate 1RM'.
Review your estimated max and the percentage training chart.
Frequently Asked Questions
1RM formulas lose accuracy if the reps exceed 10. For the most accurate calculation, use a weight you can only lift 3 to 5 times.
The Epley and Brzycki formulas are the gold standards. Our tool calculates both and provides the average.
All file processing is performed locally in your web browser. We do not upload, store, or view your data.