Estimate your 1RM using Epley, Brzycki, Lombardi, and O'Conner formulas. Get training percentages instantly.
| Formula | Estimated 1RM |
|---|---|
| Epley | 116.7 kg |
| Brzycki | 112.5 kg |
| Lombardi | 117.5 kg |
| O'Conner | 112.5 kg |
| Average | 114.8 kg |
| % of 1RM | Weight | Approx Reps |
|---|---|---|
100% | 114.8 kg | 1 |
95% | 109.0 kg | 2 |
90% | 103.3 kg | 4 |
85% | 97.6 kg | 6 |
80% | 91.8 kg | 8 |
75% | 86.1 kg | 10 |
70% | 80.3 kg | 12 |
65% | 74.6 kg | 15 |
60% | 68.9 kg | 18 |
50% | 57.4 kg | 20+ |
Free 1RM calculator to estimate your one rep max from any weight and rep combination. Uses four proven formulas — Epley, Brzycki, Lombardi, and O'Conner — then averages them for the most accurate estimate. Instantly see training percentages so you know exactly how much weight to load for any rep range.
The Epley formula calculates 1RM as weight × (1 + reps / 30). Brzycki uses weight × (36 / (37 − reps)). Lombardi computes weight × reps^0.10, and O'Conner uses weight × (1 + reps × 0.025). Each formula has strengths at different rep ranges, so averaging all four gives the most reliable prediction. The calculator works for any barbell or dumbbell exercise including bench press, squat, deadlift, and overhead press.
Once you know your estimated 1RM, you can program your training using percentages. Heavy singles and doubles at 95–100% build maximal strength. Working sets at 80–85% for 6–8 reps develop hypertrophy and strength. Lighter loads at 60–70% for 12–18 reps build muscular endurance. The training percentage table updates automatically based on your estimated max.
Strength training goes hand in hand with tracking your body composition and nutrition. Use our body fat calculator to monitor changes in fat mass and lean mass as you progress. Pair your training with the calorie calculator to make sure you are eating enough to support muscle growth and recovery.
Monitor your training intensity with the heart rate calculator or dial in your running pace with the pace calculator.