What is a 1-Rep Max (1RM)?
Your One-Repetition Maximum (1RM) is the maximum weight you can lift for one repetition with correct execution on a given exercise. It is the gold standard metric used in powerlifting, Olympic lifting, and general strength coaching to determine relative strength capacity.
The Epley Formula
Testing your actual 1RM can cause central nervous fatigue and carries a higher risk of injury. This calculator safely estimates your 1RM using the clinical Epley Formula:
1RM = Weight Lifted × (1 + Reps Completed ÷ 30)
How to Structure Strength Cycles
With your estimated 1RM, you can program daily working weights based on percentage-based training splits:
- Neurological Absolute Power: 85% – 95% of 1RM (1 to 5 reps per set).
- Muscular Hypertrophy: 70% – 80% of 1RM (6 to 12 reps per set).
- Local Muscular Endurance: 60% – 68% of 1RM (15+ reps per set).