What this calculator tells you
RPE based on repetitions in reserve helps adapt a plan to daily readiness. This tool turns planned repetitions and target effort into a transparent load estimate.
How to use the RPE / RIR Load Calculator
- 1
Enter a recent 1RM estimate and planned reps.
- 2
Choose target RPE from 6 to 10.
- 3
Adjust the suggested load during warm-ups to match the intended effort.
Formula and interpretation
Method
Estimated repetitions to failure = planned reps + RIR, where RIR = 10 − RPE. The Epley relationship is then inverted to estimate load from 1RM.
How to read the result
Start near the estimate and adjust after warm-ups. The set should end with roughly the planned number of clean repetitions still available.
Important limitations
People often misjudge repetitions in reserve, especially far from failure or with little experience. Treat the output as a starting load.
RPE / RIR Load Calculator questions
What is the difference between RPE and RIR?
On the common resistance-training scale, RPE 10 is about 0 RIR, RPE 9 about 1 RIR, and so on.
Why did the suggested load feel wrong?
Readiness, exercise skill, and the 1RM estimate all vary. Autoregulation means adjusting rather than obeying the first number.
