1 Rep Max Calculator
Estimate your absolute strength safely and calculate precise training percentages for your next workout program.
This calculator auto-updates when values change.
Estimated 1 Rep Max
116.7 kg
1RM is an estimate, not a guarantee.
Training Percentages
| Percent | Weight (kg) | Est. Reps |
|---|---|---|
| 100% | 116.7 | 1 |
| 95% | 110.8 | 2 |
| 90% | 105 | 3-4 |
| 85% | 99.2 | 5-6 |
| 80% | 93.3 | 7-8 |
| 70% | 81.7 | 11-12 |
| 60% | 70 | 16-20 |
| 50% | 58.3 | 20+ |
This calculator provides simplified strength estimates only. It is not medical, fitness, or professional coaching advice. Use safe technique and avoid testing max lifts without proper preparation or supervision.
Based on lifting 100kg for 5 reps, your estimated one rep max is 116.7 kg. Training percentages are calculated from that estimated maximum.
About This 1 Rep Max Calculator
This 1 rep max calculator estimates the maximum weight you could lift for one repetition based on a submaximal set.
Instead of testing your true maximum, you can enter a weight you lifted for multiple reps and use the result to plan training percentages.
The estimate is useful for strength training, progressive overload, and workout programming, but it should not be treated as a guaranteed lift.
How to Use This Calculator
- 1
Enter the weight lifted
Add the amount of weight you successfully lifted for your working set.
- 2
Enter completed reps
Add the number of good-form reps you completed with that weight.
- 3
Choose a formula
Use Epley as the standard option, or compare with Brzycki and Lombardi.
- 4
Review training percentages
Use the percentage table to plan lighter working sets based on your estimated max.
Frequently Asked Questions
What is a one rep max?v
A one rep max is the maximum amount of weight you are estimated to lift for one complete repetition of an exercise.
How accurate is a 1 rep max calculator?v
A 1 rep max calculator gives an estimate based on weight and reps. It is useful for planning training loads, but it is not a guaranteed maximum.
Which formula should I use?v
The Epley formula is a common default. Other formulas may give slightly different estimates, especially when reps are higher.
Should beginners test a true one rep max?v
Most beginners should avoid true max testing and use estimated maxes instead. This is safer and still useful for programming workouts.