Strength
RPE Calculator
Updated 1 Nov 2026 · Source: Zourdos et al. (2016) RPE scale ↗
Enter the weight, the reps and how hard the set felt on the RPE scale, and the calculator estimates your max and a load for your next set at RPE 8.
Worked example
- RPE 8 means about 2 more reps were possible.
- So the set counts like 7 reps to failure.
- Average of Epley, Brzycki and Lombardi for 225 lb × 7 reps = 274 lb
Share of your max for reps and RPE (our reps-in-reserve method)
| Reps | RPE 10 | RPE 9 | RPE 8 | RPE 7 |
|---|---|---|---|---|
| 1 | 100.0% | 95.5% | 92.7% | 90.0% |
| 2 | 95.5% | 92.7% | 90.0% | 87.3% |
| 3 | 92.7% | 90.0% | 87.3% | 84.7% |
| 4 | 90.0% | 87.3% | 84.7% | 82.2% |
| 5 | 87.3% | 84.7% | 82.2% | 79.8% |
| 6 | 84.7% | 82.2% | 79.8% | 77.4% |
| 8 | 79.8% | 77.4% | 75.0% | 72.7% |
| 10 | 75.0% | 72.7% | 70.4% | 68.2% |
RPE and reps in reserve
RPE stands for rating of perceived exertion. In strength training it is usually tied to reps in reserve, meaning how many more reps you could have done when you racked the bar.
This version of the scale was introduced in a 2016 study of 29 lifters by Zourdos and colleagues. RPE 10 means no reps left, RPE 9 means one rep left, and RPE 8 means two reps left.
How our method converts it
The calculator adds the reps you had left to the reps you did. A set of 5 at RPE 8 counts like 7 reps to failure. That set count then goes through the same average of Epley, Brzycki and Lombardi we use on the one rep max calculator.
For the default set of 225 lb for 5 at RPE 8, the estimate is about 274 lb (124 kg). Half steps count as half a rep, so RPE 8.5 means about 1.5 reps left.
Using the table to plan sets
The table below the calculator shows what share of your max fits each rep and RPE pair. Five reps at RPE 8 sit at 82.2% of the max, while five reps at RPE 10 sit at 87.3%.
Many programs write sets as reps at an RPE, such as 5 at RPE 8. Read the matching cell, multiply by your max and round to a weight you can load. Look up straight rep maxes in the rep max chart.
Limits below RPE 7
People judge reps in reserve best when they are close to failure. With more than three reps left, guesses get less precise, so the calculator warns you when you pick an RPE below 7.
For an estimate you can trust, use a set rated RPE 8 or higher. Light warm up sets are fine for practice rating, but not for setting a max.
Getting better at rating sets
Rating effort is a skill. In the 2016 study, RPE matched bar speed closely, more so in experienced lifters (r = −0.88) than in novices (r = −0.77).
To practice, rate a set before you rack the bar, then now and then take a set to failure safely and see how close your guess was. Use a spotter or safety bars on sets you push that hard.
Related pages
DOTS Calculator, One Rep Max Formula, Wilks Formula Calculator, Rep Max Chart
Questions
What does RPE 8 mean?
You finished the set with about two reps left. It is a common target for hard working sets because it leaves some room before failure.
Is RPE the same as reps in reserve?
They describe the same thing from two sides. RPE 10 equals zero reps in reserve, and each step down adds one rep in reserve.
Can I use RPE for progressive overload?
Yes. If the same weight and reps feel easier over a few weeks, your max has probably gone up. See progressive overload for ways to add load.
How we calculate: every formula, with its author and year, is on our method page; data sources and their licenses are on sources.
gymnical.com gives estimates from published formulas and public data. It is not medical advice and not a training prescription. Last reviewed November 2026.