RPE Chart for Lifting: RPE and Reps in Reserve (RIR) Explained
"Do 3 sets of 8" leaves out the most important detail: how hard should those sets be? Eight reps with a weight you could lift 20 times is a warm-up. Eight reps with a weight you could barely lift 8 times is a grinder. RPE and reps in reserve (RIR) fill that gap.
The RPE chart for lifting
This is the repetitions-in-reserve-based RPE scale used in strength training. It was formalized in a 2016 paper by Zourdos and colleagues and is now standard in most lifting programs.
| RPE | Reps in reserve (RIR) | What it feels like |
|---|---|---|
| 10 | 0 | Maximal effort. No more reps, no more weight. |
| 9.5 | 0 | No more reps, but you could have added a little weight. |
| 9 | 1 | One more rep was possible. |
| 8.5 | 1–2 | Definitely one more, maybe two. |
| 8 | 2 | Two more reps were possible. |
| 7.5 | 2–3 | Definitely two more, maybe three. |
| 7 | 3 | Three more reps. The bar still moves quickly. |
| 5–6 | 4–6 | Moderate effort. Good for technique work and warm-ups. |
| 1–4 | 6+ | Light to very light. Warm-up territory. |
The simple conversion: RPE = 10 − RIR. If you prefer counting reps left, use RIR. If you like a 1–10 rating with half-steps near the top, use RPE. They measure the same thing.
Why RPE beats "just do the reps"
Your strength isn't the same every day. Sleep, stress, food, and leftover fatigue from earlier sessions can move it up or down. A fixed weight that's RPE 7 on a great day might be RPE 9.5 on a rough one.
Effort-based targets adjust for that automatically. A program that says "squat 3 × 5 at RPE 8" tells you to pick whatever weight leaves about two reps in the tank today. A 2016 applied review by Helms and colleagues describes this as the main advantage of the RIR-based scale: it lets you individualize load from day to day instead of guessing.
How accurate are RPE ratings?
Honestly, not perfectly, and that's worth knowing before you put too much faith in a single rating.
A 2022 meta-analysis by Halperin and colleagues pooled 12 studies with 414 participants. On average, people underestimated their reps to failure by about one rep. In other words, they had a little more in the tank than they thought. Three findings are useful:
- Accuracy improves closer to failure. Your RPE 9 is more reliable than your RPE 6.
- Accuracy improves with heavier loads (sets of 12 reps or fewer) compared with very high-rep sets.
- Accuracy improves on later sets of the same exercise.
Training experience didn't make much difference, which is reassuring for newer lifters. Everyone is a bit off, and everyone gets better with practice.
How to calibrate: occasionally take a final set of a safe exercise, like a machine press or leg extension, to true failure, and compare your actual reps with what you predicted. Do this a few times and your ratings get noticeably sharper.
What RPE should you train at?
Most productive training happens between RPE 7 and 9, or 1–3 reps in reserve.
| Situation | Suggested effort |
|---|---|
| Heavy compound lifts (squat, deadlift, bench) | RPE 7–8.5 (1.5–3 RIR) |
| Machines and isolation exercises | RPE 8–10 (0–2 RIR) |
| Technique practice, deload weeks | RPE 5–7 (3–5 RIR) |
| Testing a new max | RPE 9.5–10 |
Why stay further from failure on big barbell lifts? The injury and fatigue cost of a missed rep is higher, and form tends to degrade first. On a leg extension, an extra rep near failure is low risk.
The research supports going reasonably hard for muscle growth. A 2024 series of meta-regressions by Robinson and colleagues found that the hypertrophy estimates favored sets ending nearer the limit, whereas the strength estimates showed little relationship with the number of repetitions left unfinished. In practice, that means you don't need to grind heavy sets to build strength, but your hypertrophy sets should feel genuinely hard. For more, see training to failure.
How to use RPE in your program
- Start with a target. For example, "Bench press 3 × 8 @ RPE 8."
- Pick a weight you expect to land near that RPE.
- Rate the set honestly right after you rack it.
- Adjust the next set. Too easy (RPE 6.5)? Add weight. Too hard (RPE 9.5)? Drop a little.
- Log both the numbers and the rating. Next session, the RPE tells you whether last week's 80 kg × 8 was a grinder or had room to spare, and that decides whether you add weight.
RPE also makes progressive overload more honest. If you hit 100 kg × 5 at RPE 9 last week and 100 kg × 5 at RPE 7.5 this week, you got stronger even though the bar didn't change.
Tracking RPE and RIR in ForgeLyte Lift
ForgeLyte Lift Pro includes effort tracking. Choose RPE (1–10 in half-steps) or RIR (0–10) in Settings, then rate each set right next to its weight and reps. Your rating is saved with the set in your workout history, so you can look back at how hard last week's sets really were. Combined with set types (warm-up, working, failure) and automatic PR detection, it gives you a complete picture of each set.
Frequently asked questions
What is the difference between RPE and RIR?
What RPE should I train at?
What does RPE 9.5 mean?
Are beginners accurate at rating RPE?
Is RPE better than percentage-based training?
Sources
- Zourdos MC, et al. Novel resistance training-specific rating of perceived exertion scale measuring repetitions in reserve (2016). J Strength Cond Res.
- Helms ER, et al. Application of the repetitions in reserve-based rating of perceived exertion scale for resistance training (2016). Strength Cond J.
- Halperin I, et al. Accuracy in predicting repetitions to task failure in resistance exercise: a scoping review and exploratory meta-analysis (2022). Sports Med.
- Robinson ZP, et al. Exploring the dose-response relationship between estimated resistance training proximity to failure, strength gain, and muscle hypertrophy (2024). Sports Med.
Written by the developer of ForgeLyte Lift, a workout tracker mentioned in this guide. This article is general information, not medical advice. Talk to a qualified professional before starting a new training program, especially if you have an injury or health condition.