About the One Rep Max Calculator
Estimate the most you could lift for a single rep from a set you've completed, using three well-known formulas, and get training weights from 50% to 100% of your max.
Key features
- Epley, Brzycki and Lombardi formulas
- Average estimate
- Training weights from 50% to 100%
- Typical reps at each percentage
- kg or lb
- No max-out test needed
Estimate your one-rep max
Enter a weight and the number of reps you completed to estimate your one-rep max, then use the percentage chart to choose weights for strength, hypertrophy or endurance training.
The formulas
| Formula | Equation |
|---|---|
| Epley | 1RM = weight × (1 + reps ÷ 30) |
| Brzycki | 1RM = weight × 36 ÷ (37 − reps) |
| Lombardi | 1RM = weight × reps^0.1 |
Example
100 kg for 5 reps gives an estimated 1RM of about 115 kg (Epley 116.7, Brzycki 112.5, Lombardi 117.5).
Training zones by % of 1RM
| % of 1RM | Reps | Goal |
|---|---|---|
| 85–100% | 1–5 | Maximum strength |
| 70–85% | 6–12 | Muscle growth (hypertrophy) |
| 50–70% | 12–20+ | Muscular endurance |
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How to use the One Rep Max Calculator
- Enter your numbers in the fields above. Units and options can be changed at any time.
- The result updates instantly as you type; there's no calculate button to press.
- Check the breakdown under the main result for the details behind the number.
- Adjust the inputs to compare scenarios, for example a different rate or term.