How to Use RPE and RIR in Training: Practical Application Guide

Go beyond the definitions. Learn the practical day-to-day application of autoregulated training for consistent progress.

RPE 8 = 2 RIR (2 Reps in Reserve). The formula is: RIR = 10 – RPE. So RPE 9 = 1 RIR, RPE 10 = 0 RIR (failure). For hypertrophy, train most sets at RPE 7-8 (RIR 2-3).

Convert between RPE and RIR, calculate estimated 1RM from your working sets.

Before diving into application, let’s clarify the two scales. RPE (Rate of Perceived Exertion) runs from 1-10, where 10 means maximum effort (failure). RIR (Reps in Reserve) counts how many more reps you could do: RIR 2 means you had 2 reps left in the tank.

The relationship is simple: RPE = 10 – RIR. So RIR 2 equals RPE 8, and RIR 0 equals RPE 10 (failure). Most modern programs use RIR because it’s more intuitive for lifters to think “how many more could I do?” rather than rating effort on a scale.

For a detailed breakdown of the scales and conversion chart, see our RPE/RIR Calculator or the glossary definitions.

The choice between autoregulation (RPE/RIR) and percentage-based training depends on your goals, training phase, and individual factors:

Arvo monitors your RIR every set and adjusts your next set’s target weight in real-time. No manual calculations, no guesswork—just intelligent progression based on how you’re actually performing.