e1RM calculator
Estimate your one-rep max from a safe working set. Three formulas, a confidence rating and ready percentage-based loads.
Everything is computed in your browser โ the values you enter are never sent or stored.
Result
- Estimated 1RM (Epley)
- 116.7 kg
- Brzycki
- 112.5 kg
- Lombardi
- 117.5 kg
- Confidence
- estimate
Percentage loads
| % 1RM | Weight | Typical use |
|---|---|---|
| 95% | 110.8 kg | max strength, 1-2 reps |
| 85% | 99.2 kg | strength, 3-5 reps |
| 75% | 87.5 kg | hypertrophy, 8-10 reps |
| 65% | 75.8 kg | volume, 12-15 reps |
| 50% | 58.3 kg | technique, warm-up |
Do not test a true 1RM without experience and a spotter. Estimating from a working set is safer and good enough for planning.
How we calculate this
- Epley: e1RM = weight ร (1 + reps / 30)
- Brzycki: e1RM = weight ร 36 / (37 โ reps)
- Lombardi: e1RM = weight ร reps^0.10
The formulas come from the appโs domain specification and are covered by unit tests. The same code powers zones inside the app.
Explore Trenaio plans
In the dashboard you can log workouts and use the training plan included in your tier. New account registration is currently closed.
This calculator is informational and does not replace a doctor, physiotherapist or coach. Results based on population formulas are estimates, not measurements. Read the full disclaimer โ