What This Tool Does
The 1RM One-Rep Max Calculator estimates your one-rep max from training weight and reps, then provides practical load targets by percentage so you can plan bench press, squat, deadlift, and strength cycles more consistently.
How to Use
- Choose an exercise and enter working weight plus reps to failure.
- Select the unit (kg or lb), and switch formulas when needed.
- Review estimated 1RM, 60%-95% training loads, and guidance text.
- Compare formula outputs and use the value that best matches your training profile.
Formulas
- Epley:
1RM = weight × (1 + reps/30) - Brzycki:
1RM = weight × 36/(37 - reps) - Lander:
1RM = 100 × weight/(101.3 - 2.67123 × reps) - O'Conner:
1RM = weight × (1 + 0.025 × reps) - Average: mean value of Epley, Brzycki, and Lander
Intensity Reference
- 50%-60% 1RM: warm-up and movement activation.
- 60%-70% 1RM: endurance focus, often 12-20 reps.
- 70%-80% 1RM: hypertrophy focus, often 8-12 reps.
- 80%-90% 1RM: strength focus, often 4-6 reps.
- 90%-100% 1RM: power or peak-strength phases, often 1-3 reps.
Notes
- Results are estimates, and real 1RM depends on technique, fatigue, and training history.
- Use safeties or a spotter before attempting near-max or max lifts.
- Retest every 4-6 weeks to keep loads aligned with progress.
- All calculations run locally in your browser and no training data is uploaded.