One Rep Max Calculator
Estimate your 1RM for any lift from a submaximal set — using the most accurate formulas in sports science. No max attempts required.
1RM Calculator
Epley · Brzycki · Lander · Lombardi
One Rep Max estimation lets you program percentage-based training without risking injury from max attempts. Best results come from sets of 2–6 reps — estimates from sets of 10+ have higher error margins. Use this to set your training percentages for programs like 5/3/1, Juggernaut, or any block training system.
Epley formula: 1RM = weight × (1 + reps/30). Most consistent across lifts and rep ranges.
Percentage-Based Training Table
Once you know your 1RM, use these percentages to set your training weights:
| % of 1RM | Rep Target | Training Focus |
|---|---|---|
| 95–100% | 1–2 | Competition / max testing |
| 85–92% | 3–5 | Strength development |
| 75–85% | 5–8 | Strength-hypertrophy |
| 65–75% | 8–12 | Hypertrophy |
| 50–65% | 12–20 | Endurance / technique |
Formula Comparison
Your One Rep Max (1RM) is the maximum weight you can lift for a single complete repetition with correct form on any given exercise. It is the universal standard for measuring absolute strength and the foundation of all percentage-based training programming. Rather than risking injury with true maximal attempts in routine training, 1RM estimation from submaximal sets — using validated mathematical formulas — is the standard practice in competitive powerlifting, athletic performance, and general strength training. The four most widely validated formulas are: Epley (w × (1 + r/30)), Brzycki (w × 36/(37-r)), Lander, and Lombardi. This calculator averages all four to produce the most robust estimate. All formulas are most accurate for submaximal sets of 2–6 reps — estimation error increases substantially at 10+ reps because individual fatigue resistance varies widely between athletes. Once you know your 1RM, you can set accurate training weights for any strength or hypertrophy programme by applying the percentage table below.