RPE calculator
Add a target set (optional)
Estimated one-rep max
Estimated weight for your target
These numbers are estimates based on the set you entered. Use them as a starting point, not a prescribed load, and adjust to how the set actually feels. Stop an exercise if it causes pain.
Designed for people who already use RPE in resistance training and are entering an exercise they already perform.
Already have a set you took to failure? The one rep max calculator estimates your max from weight and reps alone.
How it works. The calculator uses the whole-number ratings of the lifting RPE scale below: RPE 10 means no reps left, RPE 9 one, RPE 8 two and RPE 7 three. Based on the RPE you enter, it adds those reps in reserve to the reps you completed to estimate how many repetitions the set might have reached at failure. It then applies the Brzycki equation: weight lifted / (1.0278 - 0.0278 × reps to failure).
Brzycki developed that equation for repetitions performed to fatigue and limited its use to fewer than 10 repetitions. The step of estimating reps to failure from RPE is an additional estimation used by this calculator; it is not part of the Brzycki or Zourdos methods, and the combined calculator was not validated in those publications.
For that reason, the calculator only produces a result when both the set you entered and the target set correspond to fewer than 10 estimated repetitions to failure. It then works back from the estimate for your target reps and RPE and rounds to the nearest increment you choose. Every result is an estimate. The calculation runs in your browser.
RPE chart: the RPE scale for lifting
| RPE | What it means |
|---|---|
| 10 | Maximum effort. No reps left. |
| 9.5 | No more reps, but you could have added a little weight. |
| 9 | 1 rep left. |
| 8.5 | 1 or 2 reps left. |
| 8 | 2 reps left. |
| 7.5 | 2 or 3 reps left. |
| 7 | 3 reps left. |
| 5 to 6 | 4 to 6 reps left. |
| 3 to 4 | Light effort. |
| 1 to 2 | Little to no effort. |
Adapted from Zourdos and colleagues (2016).
What RPE means in strength training
In strength training, RPE is often a 1 to 10 rating tied to reps in reserve, or RIR: how many more reps you could have done with the same weight. RPE 10 means you had nothing left, RPE 9 means one rep left, and RPE 8 means two. This version of the scale was used in powerlifting before Zourdos and colleagues tested it in a 2016 study.
How to rate a set
Rate the set right after you finish it. Ask how many more reps you could have done with the same weight, then find that number on the chart. For ratings between 7 and 10, the chart includes half steps at 7.5, 8.5 and 9.5. The calculator takes whole numbers only.
How coaches use RPE in a program
Coaches who program with RPE write a target next to the sets and reps. "4 x 5 at RPE 8" means four sets of five reps, with a weight that leaves about two reps in reserve. Instead of a fixed weight, the client picks the weight that matches the target on the day, so the load can move with how they are performing. Helms and colleagues (2016) describe this as adjusting loads to the athlete set by set.
RPE for lifting is not the cardio RPE scale
Other RPE scales rate overall effort during exercise such as cardio. The Borg scale runs from 6 to 20, and a modified version, the Borg CR10, runs from 0 to 10 (Cleveland Clinic). The scale on this page is the resistance training version, based on reps in reserve.
Frequently asked questions
What does RPE stand for?
Rating of perceived exertion. On this page, it means the reps in reserve scale in the chart above.
What is an RPE chart?
The chart on this page maps each lifting RPE rating to its meaning in reps in reserve or perceived effort.
What does RPE 8 mean?
You finished the set with about two reps in reserve: you could have done two more reps with the same weight.
What does RPE 7 mean?
You finished the set with about three reps in reserve: you could have done three more reps with the same weight.
Is RPE the same as RIR?
On this lifting scale, RPE is linked to RIR. RPE 10 corresponds to 0 RIR, RPE 9 to 1 RIR, RPE 8 to 2 RIR and RPE 7 to 3 RIR.
How do you calculate RPE?
RPE is a rating, not a measurement. After a set, ask how many more reps you could have done with the same weight and find that number on the chart. The calculator above uses that rating to estimate weights.
How accurate is an RPE calculator?
Treat the result as an estimate. It depends on how accurately the set was rated, on the extra step of estimating reps to failure from RPE, and on the Brzycki equation, which Brzycki limited to fewer than 10 repetitions. Adjust to how the set actually feels.
For coaches
Wolvec is an AI platform for fitness coaches and online personal trainers, the whole coaching setup rather than an add-on to it. Your AI drafts each program week based on how you coach and the client's intake, and you approve the week before the client sees it.
Sources
- Zourdos MC and colleagues. Novel resistance training-specific rating of perceived exertion scale measuring repetitions in reserve. Journal of Strength and Conditioning Research, 2016; 30(1):267 to 275.
- Helms ER, Cronin J, Storey A, Zourdos MC. Application of the repetitions in reserve-based rating of perceived exertion scale for resistance training. Strength and Conditioning Journal, 2016; 38(4):42 to 49.
- Brzycki M. Strength testing: predicting a one-rep max from reps-to-fatigue. Journal of Physical Education, Recreation and Dance, 1993; 64(1):88 to 90.
- Cleveland Clinic: Rated Perceived Exertion (RPE) Scale.