RPE, RIR & %1RM Converter
Prescribe working loads by reps in reserve rather than a fixed percentage, so the weight adjusts to how you are actually performing.
- 01Enter your one-rep max for the lift.
- 02Choose a rep target and how many reps you want to leave in reserve.
- 03Or switch modes to find out what RPE a weight you used actually represented.
What the terms mean
- RPE
- Rate of perceived exertion on the 1–10 lifting scale. RPE 10 is a maximal effort.
- RIR
- Reps in reserve. RPE = 10 − RIR, so RPE 8 means two reps left.
- %1RM
- The proportion of your one-rep max a load represents.
- Autoregulation
- Adjusting the day’s load to how you are actually performing.
Percent of 1RM for 5 reps across reps-in-reserve.
Method & sources
RPE here is the repetitions-in-reserve scale: RPE 10 means no reps left, RPE 8 means two in reserve. This is more useful than a fixed percentage because it self-adjusts to daily readiness — the same 80% feels very different after a bad night's sleep.
Research validating the scale found trained lifters estimate proximity to failure reasonably well, particularly within a few reps of it. Accuracy is lower in novices and at high rep counts, so treat the percentages as approximate rather than exact.
Zourdos MC et al., J Strength Cond Res 2016 · Helms ER et al., J Strength Cond Res 2017
What these numbers
actually tell you.
Why RPE beats fixed percentages
A percentage is a fixed prescription applied to a body whose readiness changes daily with sleep, stress, food and accumulated fatigue. Eighty percent on a good day and after a bad night are the same number and very different sets. Prescribing by reps in reserve lets the load track your actual capacity.
How accurate is your own RPE judgement
Research validating the scale found trained lifters estimate proximity to failure reasonably well, particularly within a few reps of it. Accuracy is lower in novices, at high rep counts, and on lifts you have less experience with. If you are new, expect to under-rate difficulty — most people think they are closer to failure than they are.
Using this for programming
A common approach is to work at RPE 7–8 for most volume work, leaving two to three reps in reserve, and reserve RPE 9–10 for occasional testing. Accumulating too many sets at RPE 10 builds fatigue faster than it builds capacity.
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