RPE Calculator
Turn a set you rated by RPE into an estimated max, and see what to load for any reps and RPE your program asks for.
Your details
Your results
Enter a set's weight, reps and RPE to see your estimated max and an RPE chart.
Estimated one rep max
From : about reps to failure.
| Reps | RPE 7 | RPE 8 | RPE 9 | RPE 10 |
|---|---|---|---|---|
| 1 | ||||
| 2 | ||||
| 3 | ||||
| 4 | ||||
| 5 | ||||
| 6 | ||||
| 8 | ||||
| 10 | ||||
| 12 |
How to use it
- Enter the weight and reps of a set you've done.
- Pick how hard it was on the RPE scale. RPE 8 means you had 2 reps left, RPE 10 means none.
- Read your estimated one rep max.
- Use the chart to find the weight for a target, such as 5 reps at RPE 8. Weights are rounded to plates.
How it's calculated
The RPE scale. The calculator uses the reps-in-reserve (RIR) scale from Zourdos and colleagues (2016):
| RPE | Meaning |
|---|---|
| 10 | Max effort, no reps left |
| 9.5 | No reps left, but a bit more weight was possible |
| 9 | 1 rep left |
| 8.5 | 1 to 2 reps left |
| 8 | 2 reps left |
| 7.5 | 2 to 3 reps left |
| 7 | 3 reps left |
Your estimated max. A set of r reps at RPE x is treated as a set you could have taken to r + (10 − x) reps. That number goes into the same formulas as the One Rep Max Calculator, the average of Epley (w × (1 + n ÷ 30)) and Brzycki (w × 36 ÷ (37 − n)). Example: 100 kg × 5 at RPE 8 counts as 7 reps to failure, an estimated max of about 122 kg.
The chart. Each cell solves the same formula the other way round: the weight you could lift for that many reps with that many reps left. Weights are rounded to 2.5 kg or 5 lb.
Limits. The 1RM formulas lose accuracy above about 10 reps to failure, so the calculator accepts sets of up to 12 reps.
Sources
- Zourdos, M. C., Klemp, A., Dolan, C., Quiles, J. M., Schau, K. A., Jo, E., Helms, E., Esgro, B., Duncan, S., Garcia Merino, S., & Blanco, R. (2016). Novel resistance training-specific rating of perceived exertion scale measuring repetitions in reserve. Journal of Strength and Conditioning Research, 30(1), 267–275.
- Helms, E. R., Cronin, J., Storey, A., & Zourdos, M. C. (2016). Application of the repetitions in reserve-based rating of perceived exertion scale for resistance training. Strength and Conditioning Journal, 38(4), 42–49.
- Epley, B. (1985). Poundage Chart. Boyd Epley Workout. Lincoln, NE: Body Enterprises.
- Brzycki, M. (1993). Strength testing: predicting a one-rep max from reps-to-fatigue. Journal of Physical Education, Recreation & Dance, 64(1), 88–90.
Questions
What does RPE mean in lifting?
Rating of perceived exertion. In lifting, it's tied to reps in reserve, the reps you could still have done. RPE 10 means you couldn't do another rep, RPE 9 means one more, RPE 8 means two more.
Why does the chart stop at RPE 7?
Below RPE 7, the scale only gives a range (RPE 5 to 6 means 4 to 6 reps left), so a single weight would be a guess. People are also less accurate at judging easy sets.
How accurate is it?
As accurate as your RPE rating. Experienced lifters rate their reps in reserve more accurately than beginners, and everyone is more accurate close to failure. Rate honestly and the numbers will follow.
How is this different from the One Rep Max Calculator?
The One Rep Max Calculator assumes your set went to (near) failure. This one takes into account how many reps you had left, so it works for the submaximal sets most programs use.
Updated November 9, 2026.