How to Calculate RPE
RPE and RIR are the same measurement read from opposite ends. Pick the end you already think in.
The two scales
RPE — Rate of Perceived Exertion — rates how hard a set felt on a scale of 1 to 10, where 10 means you could not have done another rep.
RIR — Reps In Reserve — counts the reps you had left in the tank when you racked it. RIR 0 is a set taken to failure.
They map onto each other exactly: RIR 2 is the same set as RPE 8. RIR 1 is RPE 9. RIR 0 is RPE 10. Neither is more precise than the other, so the useful question is only which one you can estimate honestly while out of breath.
Why log it at all
Weight and reps record what happened. Effort records what it cost, and that is the part that predicts what you should do next week. Two sets of five at the same weight are not the same set if one was RPE 7 and the other was RPE 10.
Over time it is also the earliest warning that something is off: the same weights getting harder, week over week, shows up in effort long before it shows up in the numbers on the bar.
Switching scales in Gym Journal
- Open Settings.
- Choose Effort Scale.
- Pick RPE or RIR. Nothing you have already logged changes — it is a display choice, not a rewrite.
It’s free, and it’s in the app
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Frequently asked questions
What is RPE 8 in RIR?
RPE 8 is RIR 2 — you finished the set with about two reps left in you.
Should I log RPE on every set?
Most people log it on working sets and skip it on warm-ups. Gym Journal never requires it, so a set without an effort rating is still a complete set.
Does changing between RPE and RIR affect my history?
No. Settings → Effort Scale changes how effort is shown and entered. Everything already recorded stays exactly as it was.