💪 One Rep Max Calculator
Estimate your one rep max (1RM) without actually testing it. Use multiple formulas for accurate strength predictions.
What is One Rep Max?
One Rep Max (1RM) is the maximum amount of weight you can lift for a single repetition of a given exercise. It's a standard measure of strength used in weight training.
1RM Formulas
Epley: 1RM = weight × (1 + reps/30)
Brzycki: 1RM = weight / (1.0278 - 0.0278 × reps)
McGlothin: 1RM = (100 × weight) / (101.3 - 2.67123 × reps)
Lombardi: 1RM = weight × reps^0.10
Mayhew: 1RM = (100 × weight) / (52.2 + 41.9 × e^(-0.055 × reps))
Training Percentages
| % of 1RM | Reps | Training Goal |
|---|---|---|
| 100% | 1 | Maximum Strength |
| 90-95% | 2-3 | Strength |
| 80-85% | 5-7 | Strength/Hypertrophy |
| 70-75% | 8-12 | Hypertrophy |
| 60-65% | 15-20 | Endurance |