Free tool
RPE & RIR Calculator
Rate of perceived exertion (RPE) describes how hard a set was; reps in reserve (RIR) counts how many more reps you had left. Convert between them, estimate your 1RM from a recent set and its RPE, and find the load for your next target like “3 reps @ RPE 8”. The full chart is below.
RPE ↔ RIR
RPE 8 = RIR 2 · 2 reps left
Plan your next set
Suggested load
345 lb
3 reps @ RPE 9 · ≈ 89.2% of 1RM (approximate)
Estimated 1RM
388.4 lb
315 lb × 5 @ RPE 8 · ≈ 81.1% of 1RM (approximate)
RPE chart
Approximate % of 1RM by reps (rows) and RPE (columns).
| Reps | RPE 10 | RPE 9.5 | RPE 9 | RPE 8.5 | RPE 8 | RPE 7.5 | RPE 7 | RPE 6.5 | RPE 6 |
|---|---|---|---|---|---|---|---|---|---|
| 1 | 100% | 97.8% | 95.5% | 93.9% | 92.2% | 90.7% | 89.2% | 87.8% | 86.3% |
| 2 | 95.5% | 93.9% | 92.2% | 90.7% | 89.2% | 87.8% | 86.3% | 85% | 83.7% |
| 3 | 92.2% | 90.7% | 89.2% | 87.8% | 86.3% | 85% | 83.7% | 82.4% | 81.1% |
| 4 | 89.2% | 87.8% | 86.3% | 85% | 83.7% | 82.4% | 81.1% | 79.9% | 78.6% |
| 5 | 86.3% | 85% | 83.7% | 82.4% | 81.1% | 79.9% | 78.6% | 77.4% | 76.2% |
| 6 | 83.7% | 82.4% | 81.1% | 79.9% | 78.6% | 77.4% | 76.2% | 75.1% | 73.9% |
| 7 | 81.1% | 79.9% | 78.6% | 77.4% | 76.2% | 75.1% | 73.9% | 72.3% | 70.7% |
| 8 | 78.6% | 77.4% | 76.2% | 75.1% | 73.9% | 72.3% | 70.7% | 69.4% | 68% |
| 9 | 76.2% | 75.1% | 73.9% | 72.3% | 70.7% | 69.4% | 68% | 66.7% | 65.3% |
| 10 | 73.9% | 72.3% | 70.7% | 69.4% | 68% | 66.7% | 65.3% | 64% | 62.6% |
| 11 | 70.7% | 69.4% | 68% | 66.7% | 65.3% | 64% | 62.6% | 61.3% | 59.9% |
| 12 | 68% | 66.7% | 65.3% | 64% | 62.6% | 61.3% | 59.9% | 58.6% | 57.2% |
How to use the RPE calculator
- Choose whether to start from a recent set or from a 1RM you already know.
- For a set, enter the weight, the reps and how hard it felt (RPE 6–10).
- Pick the reps and RPE you want for your next set to see the suggested load.
- Use the chart to look up any reps × RPE combination, as a percentage or as loads.
Worked example
You squat 315 lb for 5 reps and rate it RPE 8 — you had about 2 reps left. On the chart, 5 reps @ RPE 8 is roughly 81.1% of 1RM, so your estimated 1RM is about 388.4 lb.
Next session calls for triples at RPE 9. 3 reps @ RPE 9 is about 89.2% of 1RM, which works out to 346.5 lb — 345 lb once rounded to plates.
The RPE scale at a glance
In strength training, RPE is usually rated from 6 to 10 and maps directly to reps in reserve: RIR = 10 − RPE.
| RPE | RIR | Reps in reserve (RIR) |
|---|---|---|
| 10 | 0 | Max effort — no reps left |
| 9.5 | 0.5 | 0–1 reps left |
| 9 | 1 | 1 rep left |
| 8.5 | 1.5 | 1–2 reps left |
| 8 | 2 | 2 reps left |
| 7.5 | 2.5 | 2–3 reps left |
| 7 | 3 | 3 reps left |
| 6.5 | 3.5 | 3–4 reps left |
| 6 | 4 | 4 reps left |
How the RPE chart works
The chart treats each set as “reps done + reps in reserve”. A set of 5 at RPE 8 behaves like a 7-rep max, so both share the same percentage of 1RM.
Percentages come from a reps-to-failure curve similar to the widely used powerlifting RPE chart, with half-RPE steps interpolated. They are averages — your own numbers may run a few percent higher or lower.
Assumptions and limits
All percentages are approximate. RPE is subjective, and rating it accurately takes practice — new lifters often underestimate how many reps they have left.
Estimates are most reliable at RPE 7–10 and lower rep counts. Treat suggested loads as a starting point and adjust to how the bar moves on the day.
Warm up properly, progress gradually and use safety equipment for heavy work. If you have an injury or a medical condition, check with a qualified professional first.
Frequently asked questions
What is RPE in weightlifting?
RPE (rate of perceived exertion) is a 1–10 rating of how hard a set felt. In strength training it is anchored to reps in reserve: RPE 10 means no more reps were possible, RPE 8 means about two were left.
What does RIR mean?
RIR stands for reps in reserve — the number of extra reps you could have done with good form before failing. It is another way of describing the same effort as RPE.
How do I convert RPE to RIR?
Subtract the RPE from 10. RPE 9 = 1 RIR, RPE 8 = 2 RIR, RPE 7 = 3 RIR. Half points such as RPE 8.5 mean you might have had 1 or 2 reps left.
How accurate is an RPE chart?
It is a useful average, not a precise measurement. Individual differences, the exercise and how well you rate effort all shift the numbers, so use it as a guide and adjust over time.
What RPE should I train at?
Many programs keep most working sets around RPE 6–9 (1–4 reps in reserve) and use RPE 10 sparingly. Follow your program; the calculator just turns those targets into loads.
Can I estimate my 1RM from RPE?
Yes. Divide the weight by the chart percentage for its reps and RPE. Estimates are best from heavier sets of 1–6 reps rated RPE 8 or higher.
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