Free lifting tool
RPE Calculator
Turn a set you’ve just done (weight, reps and how hard it felt) into an estimated 1RM and the right load for your next set.
Estimated 1RM
123.3 kg
5 reps @ RPE 8 ≈ 81.1% of 1RM
Plan your next set
Load 107.5 kg for 3 @ RPE 8
| Reps | RPE 10 | RPE 9 | RPE 8 | RPE 7 |
|---|---|---|---|---|
| 1 | 122.5 | 117.5 | 112.5 | 110 |
| 3 | 112.5 | 110 | 107.5 | 102.5 |
| 5 | 107.5 | 102.5 | 100 | 97.5 |
| 8 | 97.5 | 95 | 90 | 87.5 |
| 10 | 90 | 87.5 | 85 | 80 |
What is RPE?
RPE (rate of perceived exertion) rates a set by how many more reps you could have done. RPE 10 means no reps left; RPE 9 means one more; RPE 8 means two more. Half points (8.5) mean you might have got one more.
How this calculator works
It uses the widely used RTS RPE chart, which gives the percentage of your one-rep max that matches each combination of reps and RPE. Your set gives an estimated 1RM, and the chart then works out the weight for any other rep and RPE target.
RPE-based training adjusts to the day: if you’re tired, the same RPE means a lighter bar. It pairs well with readiness tracking.
Frequently asked questions
What does RPE 8 mean?
RPE 8 means you finished the set with about two good reps left. It’s a common target for main strength work.
Is RPE the same as RIR?
They’re two ways of saying the same thing: RPE = 10 − RIR (reps in reserve). RPE 8 is 2 RIR.
How accurate are RPE-based 1RM estimates?
They’re good for sets of 1–6 reps. Accuracy improves as you get better at judging RPE, which usually takes a few weeks of practice.
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