RPE to 1RM Calculator
Convert your working sets using Rating of Perceived Exertion (RPE) or Reps in Reserve (RIR) into an accurate Estimated One Rep Max (e1RM).
Enter Working Set Data
Training Load Breakdown from this e1RM
Percentages: 60% – 95%| Percentage | Weight | Target Goal | Rep Range |
|---|
How the RPE to 1RM Formula Works
Rating of Perceived Exertion (RPE) combined with Reps in Reserve (RIR) gives lifters a scientifically proven method to gauge maximal strength without burning out their Central Nervous System (CNS) on true 1RM attempts.
The RPE & RIR Relationship
The modern 10-point RPE scale is rooted in Reps in Reserve (RIR):
- RPE 10 (0 RIR): Absolute maximum effort. No additional reps or weight could be completed.
- RPE 9 (1 RIR): 1 repetition remaining before muscular failure.
- RPE 8 (2 RIR): 2 repetitions remaining before failure. Ideal baseline for standard strength building.
- RPE 7 (3 RIR): 3 repetitions remaining. Bar moved with noticeable speed and crisp technical form.
- RPE 6.5 (3–4 RIR): Moderate effort, commonly used for speed work or initial ramp-up working sets.
Mike Tuchscherer RTS Percentage Matrix
The calculator references the reactive training systems (RTS) percentage table. By adding your completed reps to your Reps in Reserve, we identify your virtual rep max: Virtual Reps = Completed Reps + (10 - RPE).
| Reps | RPE 10 (0 RIR) | RPE 9 (1 RIR) | RPE 8 (2 RIR) | RPE 7 (3 RIR) |
|---|---|---|---|---|
| 1 Rep | 100.0% | 95.5% | 92.2% | 89.2% |
| 3 Reps | 92.2% | 89.2% | 86.3% | 83.7% |
| 5 Reps | 86.3% | 83.7% | 81.1% | 78.6% |
| 8 Reps | 78.6% | 76.2% | 73.9% | 70.7% |
| 10 Reps | 73.9% | 70.7% | 67.7% | 64.4% |
Worked Example: Squat Set
Suppose you squat 140 kg (308 lb) for 5 reps @ RPE 8:
- At 5 reps @ RPE 8, you had 2 reps in reserve, which corresponds to 81.1% of your 1RM.
- Calculate 1RM:
140 kg / 0.811 = 172.6 kg (380.5 lb). - You can now program back-off sets at 70% (120 kg) or 75% (130 kg) with mathematical confidence.
Frequently Asked Questions
Everything you need to know about calculating 1RM from RPE and autoregulating your training.
RPE indicates your proximity to muscular failure. RPE 10 equals 0 reps in reserve (100% capacity for that rep range). When you perform 5 reps at RPE 8, you have 2 reps in reserve, making the set equivalent to an 7-rep maximum (~81.1% of your 1RM).
Developed by elite powerlifting coach Mike Tuchscherer, the RTS RPE chart maps combinations of 1–12 repetitions and 6.5–10 RPE to exact percentages of 1RM, allowing lifters to dynamically autoregulate training loads based on daily readiness.
Beginners often underestimate their proximity to failure by 2–4 reps. Novices should first practice standard linear progression and occasionally test safe machine or dumbbell exercises to failure to calibrate their subjective RPE judgment.
Once your top set establishes your daily e1RM, take a fixed percentage for down sets (e.g. 80% of daily e1RM for 4 sets of 5 reps). This ensures your training volume automatically scales up on strong days and reduces on fatigued days.