Free Tool
1RM Calculator
Estimate your maximum strength without the risk of lifting to failure. Get precise training percentages to take the guesswork out of your programming.
Calculator
Enter the weight and reps you lifted below.
Pro tip
Use a set of 3–5 reps at a challenging weight for the most accurate estimate.
Training Percentages
| 100% | 115 kg |
| 95% | 109 kg |
| 90% | 104 kg |
| 85% | 98 kg |
| 80% | 92 kg |
| 75% | 86 kg |
| 70% | 81 kg |
| 65% | 75 kg |
| 60% | 69 kg |
| 55% | 63 kg |
| 50% | 58 kg |
Rep Max Equivalents
| 2 reps | 108 kg |
| 3 reps | 105 kg |
| 4 reps | 101 kg |
| 5 reps | 99 kg |
| 6 reps | 96 kg |
| 7 reps | 93 kg |
| 8 reps | 91 kg |
| 9 reps | 88 kg |
| 10 reps | 86 kg |
| 11 reps | 84 kg |
| 12 reps | 82 kg |
Why Calculate Your 1RM?
Your One-Rep Max (1RM) is the maximum weight you can lift for a single repetition with proper form. It is the standard metric for tracking absolute strength and structuring progressive overload.
- •Precision Training Program weights from percentages like 70%, 80%, and 90% of your estimated max.
- •Track Progress Estimate strength gains over time without constantly testing risky heavy singles.
- •Safer Testing Use sub-maximal sets (3–8 reps) to project your max with less fatigue and lower injury risk.
The Science Behind the Math
We blend multiple peer-reviewed formulas to pick the most accurate estimate for your rep range.
Epley
w × (1 + r/30)Widely used; performs well across moderate rep ranges (3–10).
Brzycki
w / (1.0278 − 0.0278×r)Favored for lower rep ranges and heavy near-max sets (1–5).
Lombardi
w × r^0.10Conservative lower-bound estimate, useful for high-rep blending.
Beyond Static Estimates
Generic calculators assume your readiness and performance stay constant. In reality, fatigue, sleep, and training stress shift your actual output session to session.
Generic calculator misses
- •Daily readiness & fatigue fluctuations
- •Set-to-set performance variation
- •Exercise-specific strength curves
- •Auto-adjusting targets from real data
Adapt tracks automatically
- •Readiness scoring from workout history
- •Live load recommendations each set
- •Per-exercise progression curves
- •Targets that adapt to your actual output
Adapt Progresses Your Loads Automatically
Adapt tracks your execution data, estimates readiness, and recommends weights dynamically so your programming stays aligned with your actual performance.