One Rep Max (1RM) Calculator
Estimate your one-rep max lift capacity in seconds.
One Rep Max (1RM) Calculator
Calculate your maximum single-repetition lift capacity and training percentage loads based on weightlifting science.
Based on lifting 100 kg for 5 reps.
| % of 1RM | Target Weight | Target Reps | Training Focus |
|---|---|---|---|
| 100% | 115.1 kg | 1 RM | Maximal Strength |
| 95% | 109.3 kg | 2 Reps | Peak Power |
| 90% | 103.6 kg | 3 - 4 Reps | Heavy Strength |
| 85% | 97.8 kg | 5 - 6 Reps | Strength / Size |
| 80% | 92.1 kg | 7 - 8 Reps | Hypertrophy |
| 75% | 86.3 kg | 9 - 10 Reps | Hypertrophy |
| 70% | 80.6 kg | 11 - 12 Reps | Muscle Endurance |
| 65% | 74.8 kg | 15 Reps | Endurance |
| 60% | 69.1 kg | 20 Reps | Warm-up / Deload |
| 50% | 57.6 kg | Speed / Warm-up | Conditioning |
About One Rep Max (1RM) Calculator
Find your max lifting weight from your normal gym sets. Plan your lifting percentages with ease.
Your files and data are processed locally in your browser memory. Never uploaded to remote servers.
Instant access with no account, no email sign-up, no passwords, and no subscription paywalls.
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Zero data retention, no user tracking cookies, and GDPR/HIPAA friendly. Your data remains strictly yours.
Fully responsive on desktop, tablet, and mobile devices without installing software or extensions.
How to Use
- Select your movement (Bench Press, Squat, Deadlift, etc.).
- Enter the weight lifted and number of completed reps.
- Review your estimated 1RM and percentage load matrix.