RPE Calculator
Turn any working set into an estimated one-rep max. Enter the weight, reps and how hard it felt on the RPE scale, then pick a target such as 3 reps at RPE 9 to get the load to put on the bar, rounded to your plates.
Last updated:
Smallest jump your plates allow (kg or lb)
1 to 12 reps
How to use the RPE Calculator
- Choose kg or lb and the smallest load jump your plates allow.
- Enter your set: the weight, the reps you completed and the RPE you would give it.
- Pick a target: the reps and RPE you want for your next set.
- Read the e1RM and the target load, already rounded to your plates.
- Use the tables to plan other sets, or download them as CSV.
RPE chart: percentage of 1RM
The chart links reps and RPE to a percentage of your one-rep max. Moving down half a point of RPE has the same effect as doing one more rep, so the values shift by one column per rep. Reps in reserve (RIR) = 10 − RPE.
| Reps | RPE 10 | RPE 9.5 | RPE 9 | RPE 8.5 | RPE 8 | RPE 7.5 | RPE 7 | RPE 6.5 |
|---|---|---|---|---|---|---|---|---|
| 1 | 100.0% | 97.8% | 95.5% | 93.9% | 92.2% | 90.7% | 89.2% | 87.8% |
| 2 | 95.5% | 93.9% | 92.2% | 90.7% | 89.2% | 87.8% | 86.3% | 85.0% |
| 3 | 92.2% | 90.7% | 89.2% | 87.8% | 86.3% | 85.0% | 83.7% | 82.4% |
| 4 | 89.2% | 87.8% | 86.3% | 85.0% | 83.7% | 82.4% | 81.1% | 79.9% |
| 5 | 86.3% | 85.0% | 83.7% | 82.4% | 81.1% | 79.9% | 78.6% | 77.4% |
| 6 | 83.7% | 82.4% | 81.1% | 79.9% | 78.6% | 77.4% | 76.2% | 75.1% |
| 7 | 81.1% | 79.9% | 78.6% | 77.4% | 76.2% | 75.1% | 73.9% | 72.3% |
| 8 | 78.6% | 77.4% | 76.2% | 75.1% | 73.9% | 72.3% | 70.7% | 69.4% |
| 9 | 76.2% | 75.1% | 73.9% | 72.3% | 70.7% | 69.4% | 68.0% | 66.7% |
| 10 | 73.9% | 72.3% | 70.7% | 69.4% | 68.0% | 66.7% | 65.3% | 64.0% |
| 11 | 70.7% | 69.4% | 68.0% | 66.7% | 65.3% | 64.0% | 62.6% | 61.3% |
| 12 | 68.0% | 66.7% | 65.3% | 64.0% | 62.6% | 61.3% | 59.9% | 58.6% |
Formula
- e1RM = weight lifted ÷ chart percentage for (reps, RPE)
- Target load = e1RM × chart percentage for (target reps, target RPE)
Example: 140 kg × 5 @ RPE 8 → 140 ÷ 0.811 = 172.6 kg e1RM. A triple at RPE 9 is 89.2% → 154.0 kg, which rounds to 155 kg with 2.5 kg jumps.
Tips for rating RPE
- Rate the set straight after you rack the bar, asking “how many more clean reps could I have done?”
- New lifters tend to underestimate how many reps they have left; filming sets and occasionally testing a rep max helps calibrate.
- Use the e1RM from your best set of the day, and track it over weeks rather than chasing single-session numbers.
- Speed and technique matter: if form breaks down, count the set as a higher RPE.
Frequently asked questions
What does RPE mean in lifting?
RPE stands for rating of perceived exertion. In strength training it is usually tied to reps in reserve: RPE 10 means no more reps were possible, RPE 9 means one more rep was left, RPE 8 means two, and half steps such as 8.5 mean you might have managed one more.
How does an RPE calculator estimate my 1RM?
Each reps-and-RPE combination corresponds to a percentage of your one-rep max on an RPE chart. For example, 5 reps at RPE 8 is about 81.1%. Dividing the weight lifted by that percentage gives the estimated 1RM, and multiplying the e1RM by another chart percentage gives a target load.
Which RPE chart does this use?
It uses the widely used RPE percentage chart popularised by Reactive Training Systems for powerlifting, covering 1 to 12 reps and RPE 6.5 to 10. In that chart each half point of RPE is worth the same as one extra rep of reserve, so 4 reps at RPE 9 equals 5 reps at RPE 10.
Is an RPE-based e1RM more accurate than Epley or Brzycki?
It is usually more realistic for sets that were not taken to failure, because standard rep-max formulas assume every rep you could do was done. If your RPE ratings are honest, the RPE estimate accounts for the reps you left in the tank.
Why does the chart stop at 12 reps?
Rep-to-percentage relationships get less reliable as reps rise, and RPE ratings also become harder to judge on long sets. For sets above 12 reps, treat any 1RM estimate as rough.
How should I use RPE targets in training?
Programs often prescribe sets such as 3 reps at RPE 8. Use the calculator to pick a starting weight from a recent e1RM, then adjust on the day: if the set feels easier than the target RPE, add a little weight; if it feels harder, reduce it.
Are all the tools on FreeToolCabin tested for quality and accuracy?
Yes! Every tool on our site undergoes automated Q/A testing in real browser environments to ensure high precision, correct output, and zero errors. If you happen to spot a bug or have a suggestion, please contact us at [email protected] and our team will review it right away.