What RPE means
RPE stands for rating of perceived exertion. In lifting, it describes how close a set was to failure on a scale from 6 to 10. It's linked to RIR (reps in reserve): the number of extra reps you could have done.
| RPE | Reps in reserve | How it feels |
|---|---|---|
| 10 | 0 | Maximum effort, no more reps possible |
| 9.5 | 0–1 | Maybe one more rep, or more weight |
| 9 | 1 | One rep left |
| 8.5 | 1–2 | Definitely one, maybe two left |
| 8 | 2 | Two reps left |
| 7 | 3 | Fast, solid reps with three left |
| 6 | 4+ | Warm-up or speed work |
How the calculator works
A set of 5 reps at RPE 8 means you could have done 7 reps at maximum effort. The calculator adds your reps and your reps in reserve, then looks up what percentage of your max that rep count usually represents. It uses the percentage chart popularized by RPE-based powerlifting coaching, where a true single is 100%, five all-out reps are about 86% and ten all-out reps about 74%.
From there it estimates your one-rep max (e1RM) and works backwards to the weight that matches your target reps and RPE.
RPE percentage chart
Frequently asked questions
What's the difference between RPE and RIR?
They describe the same thing from opposite ends. RIR counts the reps you had left; RPE rates the effort out of 10. RPE 8 equals 2 reps in reserve, and RPE 10 equals none.
What RPE should most of my sets be?
Most strength and muscle-building programs keep working sets around RPE 7–9: hard enough to drive progress, with a rep or two left so you can recover and keep good form.
Is RPE good for beginners?
It works, but beginners often misjudge how close they are to failure. Combine RPE with a simple weight progression for your first months, and rate every set so you learn what each number feels like.
Tips for rating RPE accurately
- Rate the set straight after you rack the bar, while you still remember how the last rep moved.
- Slow last reps usually mean RPE 9 or higher, even if they feel fine.
- Beginners tend to underestimate how many reps they had left. Filming your sets helps.
