One Rep Max Calculator
Estimate your one rep max for any lift. Enter the weight and reps you can do, and we’ll calculate your 1RM using three validated formulas.
One Rep Max Calculator
Estimated 1RM
75 kg
Average of 3 formulas
Epley
76 kg
weight × (1 + reps/30)
Brzycki
74 kg
weight × 36/(37-reps)
McGlothin
75 kg
100w/(101.3-2.67123r)
Training max percentages
| % of 1RM | Weight (kg) | Typical Rep Range |
|---|---|---|
| 95% | 71 kg | 1-2 reps |
| 90% | 68 kg | 2-3 reps |
| 85% | 64 kg | 3-5 reps |
| 80% | 60 kg | 5-7 reps |
| 75% | 56 kg | 7-9 reps |
| 70% | 53 kg | 9-11 reps |
| 65% | 49 kg | 11-13 reps |
| 60% | 45 kg | 13-15 reps |
| 55% | 41 kg | 15+ reps |
| 50% | 38 kg | 15+ reps |
What is One Rep Max (1RM)?
Your one rep max is the maximum weight you can lift for a single repetition of an exercise. It’s a key metric for strength training and is used to set training weights as percentages of your max.
How the Formulas Work
Epley Formula
weight × (1 + reps / 30)
Most common, accurate for low to moderate reps
Brzycki Formula
weight × 36 / (37 - reps)
Popular in academic research
McGlothin Formula
100w / (101.3 - 2.67123r)
Good for higher rep ranges
Tips for Accuracy
- ✓Use a rep weight you can do with good form — no grinders
- ✓Best results come from sets of 2-10 reps
- ✓Formulas become less accurate above 12 reps
- ✓Use your 1RM to plan progressive overload in your training