RPE Calculator
Enter your weight, reps, and RPE to see your reps in reserve and estimated max.
| RPE | Reps in reserve |
|---|---|
| 10 | 0 |
| 9.5 | 0.5 |
| 9 | 1 |
| 8.5 | 1.5 |
| 8 | 2 |
| 7.5 | 2.5 |
| 7 | 3 |
| 6 | 4 |
What RPE and RIR mean
RPE rates how hard a set felt, from 6 up to 10. RPE 10 means no reps left, and every half point under that adds half a rep in reserve. RPE 8 means roughly two good reps were still available.
Why use RPE
RPE lets you adjust the load to how you feel on the day, so a bad-sleep session does not force a weight that is not there. It also turns a set you already did into a max estimate without a true max attempt.
Keeping RPE honest
Give the same effort across lifts and be honest about the last rep. Log what you felt and how many reps were left, then compare over weeks. Consistency matters more than the exact number on any one day.
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Questions about this calculator
What does RPE mean?
RPE stands for rate of perceived exertion, a 6 to 10 scale for how hard a set felt. RPE 10 is no reps left, and RPE 8 is about two reps left.
How do I convert RPE to reps in reserve?
Subtract RPE from 10. RPE 8 leaves two reps in reserve, RPE 9 leaves one, and RPE 10 leaves none.
Is RPE 8 heavy?
RPE 8 is a solid working set, hard but not maximal. It is a common target for building strength without grinding every rep.
How accurate is an RPE-based max?
It is close when the set is between three and eight reps at RPE 7 to 9. Very light or very high-rep sets give rougher estimates.
What is the difference between RPE and RIR?
They are two ways to say the same thing. RIR, reps in reserve, is the count of reps left, while RPE is the effort rating. RIR equals 10 minus RPE.
Should beginners use RPE?
Beginners can, but it takes practice to judge reps left. Start by leaving two to three reps in reserve and compare your estimate to how the bar moves.