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.
1RM Calculator
Estimate your one-rep max strength across multiple scientific formulas.
Why 1RM Matters
Knowing your max allows you to calculate specific training percentages (e.g., "75% of 1RM"), which is the foundation of science-based strength programming.
Primary method: Average of Epley + Brzycki (2-5 reps)(high confidence)
Training Percentages
| Percent | Weight |
|---|---|
| 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 |
Estimated Rep Maxes
| Reps | Estimated Weight |
|---|---|
| 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 |
Adapt uses your real performance data to calculate your daily readiness and adjusts your weights automatically every single set.
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
Epley Formula
Weight × (1 + Reps/30)A widely used formula with strong performance in moderate rep ranges.
Brzycki Formula
Weight / (1.0278 - 0.0278 × Reps)Commonly favored for lower rep ranges and heavier near-max sets.
Lombardi Formula
Weight × Reps ^ 0.10A more conservative estimate often used as a lower-bound reference.
Beyond Static Estimates
Generic calculators assume your readiness and performance stay constant. In reality, fatigue, sleep, and training stress change your output session to session.
- ✗Daily readiness and fatigue fluctuations
- ✗Set-to-set performance variation
- ✗Exercise-specific strength curves over time
- ✗Auto-adjusting targets based on real performance
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.