RPE vs RIR for Strength Training: Differences and Practical Use

A program calls for five squat reps at RPE 8, but the lifter records two reps in reserve. Are those the same result, or did the athlete miss the prescription? The answer affects the next set, the following week, and whether the training log contains useful information.

At LiftnLog, we treat RPE and RIR as related ways to record proximity to failure, not competing systems. A useful log keeps the planned target, actual effort, and any load adjustment separate.

Quick answer: Use this workflow when applying RPE or RIR to strength training.

1. Read RPE as a proximity-to-failure rating for the completed set.
2. Convert RPE to RIR with RIR = 10 - RPE when the set is within about four reps of failure.
3. Define a remaining rep as one completed with acceptable powerlifting technique.
4. Choose the starting load from recent performance, not an old personal record.
5. Rate the set immediately after the final rep, before reviewing video or discussing it.
6. Adjust the next set only when the rating misses the target by a meaningful amount.
7. Log the prescribed rating, actual rating, load, reps, and adjustment separately.
8. Review several sessions before changing the broader program.

RPE vs RIR for strength training: the direct comparison

For strength training, RIR means reps in reserve. It answers a narrow question: how many more technically acceptable repetitions could you have completed before failure?

RPE means rating of perceived exertion. Several RPE systems exist, but powerlifting programs commonly use a 1-to-10 scale tied directly to reps in reserve. Under that convention, RPE 10 means no reps remained, RPE 9 means one remained, and RPE 8 means two remained.

The simple conversion is:

RPE = 10 - RIR

That works best from zero to about four reps in reserve. Farther from failure, estimates become less precise. Distinguishing six remaining reps from seven rarely changes a powerlifting decision, so many lifters record an easy set as RPE 6 or lower rather than claiming exact knowledge.

RPE	Approximate RIR	What the completed set means	Typical programming response
10	0	No additional acceptable rep was available	Stop or reduce subsequent work unless maximal effort was planned
9.5	0-1	Another rep was doubtful, although slightly more load may have been possible	Usually hold or slightly reduce the next set
9	1	One acceptable rep remained	Continue if RPE 9 was prescribed; reduce if the target was RPE 7-8
8.5	1-2	One rep was certain and a second was uncertain	Make only a small adjustment if needed
8	2	Two acceptable reps remained	Common target for productive top sets without maximal fatigue
7	3	Three acceptable reps remained	Suitable for controlled volume and early training blocks
6 or lower	4 or more	The set was well short of failure	Usually treated as warm-up, technique work, or low-fatigue volume

Half-point RPE values add useful resolution without pretending that effort can be measured perfectly. RPE 8.5 does not mean exactly 1.5 repetitions remained. It means the lifter was confident about one more rep but uncertain about two.

This resistance-training-specific interpretation has been studied directly. The scale described by Zourdos and colleagues links RPE ratings to repetitions in reserve rather than relying only on general feelings of exertion, as shown in the study indexed by the National Library of Medicine.

How RPE and RIR work during a powerlifting session

Consider a lifter whose squat session prescribes one set of five at RPE 8, followed by three back-off sets of five at 90% of the top-set load. Recent training suggests that 180 kg is a reasonable starting estimate.

The lifter completes 180 kg for five. The first three reps move as expected, the fourth slows, and the fifth requires a hard grind while maintaining legal depth and control. Immediately after reracking, the lifter decides that only one more acceptable rep was available.

The actual result is therefore RIR 1, or RPE 9. The prescription was missed by one RPE point.

That does not make the set useless. It provides information. The selected load was too heavy for the requested effort on that day, whether because of accumulated fatigue, an optimistic estimate, poor sleep, or normal performance variation.

A strict percentage calculation would produce 162 kg for the back-off sets, normally rounded to 162.5 kg. Since the top set overshot its target, blindly using that number carries the error into three more sets. The lifter instead selects 157.5 kg and completes the back-offs at RPE 7, 7.5, and 8.

Record all of it: the planned top set at RPE 8, the completed 180 kg for five at RPE 9, and the decision to lower the back-off load. Do not rewrite the prescription to make the completed set look correct.

That record becomes useful the next time five reps at RPE 8 appear. Starting at 177.5 kg may be sensible if fatigue conditions are similar. If the lifter is clearly recovered and warm-ups move better, 180 kg may still be appropriate. Autoregulation responds to current evidence without treating one difficult session as a permanent loss of strength.

For a fuller load-selection process, use the examples in How to Use RPE in Powerlifting. When the session combines one heavy exposure with volume work, the top-set and back-off-set programming guide explains how the two parts should interact.

How to convert RPE to RIR without losing useful detail

The mathematical conversion is easy. The judgment behind the number takes practice.

RPE 8 converts to two RIR. RPE 9 converts to one RIR. RPE 10 converts to zero RIR. For half points, RPE 8.5 means one rep was clearly available while the second was uncertain.

Do not convert every feeling into an RPE change. A set can feel uncomfortable because the lifter is out of breath, the belt is tight, or the repetition count is high. Those sensations do not necessarily mean the muscles involved in the lift were near failure.

Rate the number of additional reps available under the standard required for that exercise. On a competition squat, another rep counts only if the lifter could reach depth and regain control. On paused bench press, a touch-and-go repetition does not count as remaining capacity. On deadlift, a rep completed by hitching or losing the required lockout is not an acceptable reserve rep.

Technical failure should usually define the endpoint. Waiting for literal physical failure can teach poor movement, create unnecessary fatigue, and increase risk when training the squat, bench press, and deadlift.

There is also a difference between repeating the same load and adding weight. At RPE 9.5, a lifter might be unable to complete another full repetition but could possibly have lifted a slightly heavier load for the same number of reps. That is why RPE 9.5 is not always interchangeable with a confident RIR 0.

When a program only accepts whole-number RIR values, record RIR 1 and add a note that a second rep was uncertain. When the log supports half-point RPE ratings, RPE 8.5 communicates that uncertainty more efficiently.

How to log RPE vs RIR consistently

Consistency matters more than choosing the supposedly superior scale. A lifter who uses RPE carefully will produce better records than one who switches between RPE and RIR based on whichever rating makes a session look better.

Choose one primary scale for daily entries. If the program prescribes RPE, rate completed sets in RPE and treat RIR as the mental question used to reach the rating. Ask, “How many more acceptable reps could I have done?” Then convert the answer.

If the program prescribes RIR, enter whole-number RIR values and use notes for uncertain cases. Avoid recording RPE 8 one week and RIR 2 the next without marking which scale was used. A bare number 8 is meaningless if nobody knows whether it describes effort, repetitions, or a subjective readiness score.

Rate the set before watching the video. Video can confirm depth, bar path, pauses, and visible slowing, but it cannot reveal with certainty how many reps remained. An athlete may also change the rating after hearing a coach’s reaction, which makes the log less representative of the athlete’s actual perception.

After assigning the initial rating, review the video and add a separate technical note. If a squat looked high or a bench pause was too short, retain the original exertion rating and mark the execution problem. Combining technical quality and proximity to failure in one number hides the reason a set went wrong.

The research record also supports treating these ratings as estimates rather than measurements. Work on the reliability of the repetitions-in-reserve RPE scale has examined how consistently trained squatters can use it, with the study details available through the National Library of Medicine. Familiarity helps, but even experienced lifters can misjudge sets that are far from failure.

Use a standard rating routine. Rerack the weight, take one breath, decide how many acceptable reps remained, and record the value. Do not wait until the end of the workout.

A useful entry contains the exercise variation, load, completed reps, prescribed effort, actual effort, and any resulting decision. Notes about sleep or soreness are helpful only when they explain an unusual result. Writing “bad day” after every difficult set adds little.

RPE vs RIR in different parts of a powerlifting program

RPE and RIR serve the same basic purpose throughout a program, but their value changes with the phase and exercise.

During a volume block, targets such as RPE 6 to 8 help keep repeated sets productive without turning every session into a test. Ratings are less precise at the easy end, so the practical question is often whether the work remained comfortably submaximal. A set rated RPE 6 instead of 6.5 rarely deserves a load change.

During a strength block, top sets at RPE 8 or 9 provide information about current performance while leaving enough capacity for back-off work. Small rating differences become more important because loads are heavier and fatigue from an overshoot can affect the rest of the week.

During meet preparation, singles may reach RPE 8 to 9 without becoming maximal attempts. The lifter can practise commands, setup, and heavy-load confidence while avoiding frequent RPE 10 work. An RPE 9 single should still look like a lift the athlete could repeat with a modest increase in effort.

Near a meet, ratings can be distorted by fatigue, anxiety, and the expectation that every heavy single predicts the final total. Review the trend rather than reacting to one session. The powerlifting taper guide explains when reducing volume is more useful than repeatedly lowering intensity.

Beginners need a narrower approach. Someone who has never approached technical failure usually cannot distinguish three reserve reps from five with much confidence. Keep early targets broad, compare ratings with video, and occasionally use safe accessory exercises to learn what true RIR 0, 1, and 2 feel like. Do not teach failure awareness by repeatedly failing squats or bench presses.

Exercise selection matters too. RIR is often easier to estimate on controlled machine or isolation work because technique is stable and failure is less disruptive. Competition deadlifts can be harder to rate because fatigue may appear suddenly, and a second rep can differ sharply from the first. Use conservative adjustments when the cost of a wrong estimate is high.

How LiftnLog supports consistent RPE and RIR decisions

A spreadsheet can handle autoregulated programming, but the user must preserve enough context to understand each number later. LiftnLog is designed around the training record, so the workflow follows the order in which the lifter makes decisions.

Start by entering the planned exercise, sets, reps, and effort target. For the worked example, that means competition squat for one set of five at RPE 8, followed by three sets of five based on the top set.

After completing the top set, record 180 kg, five reps, and the actual rating of RPE 9. The original target remains visible as the prescription rather than being replaced by the result. That difference shows whether the load matched the day.

Next, adjust the back-off work. Enter 157.5 kg rather than the initially calculated 162.5 kg, then record the rating for each completed set. The progression from RPE 7 to RPE 8 shows that fatigue accumulated without pushing the final set beyond the intended range.

When the movement returns in the program, review the previous load and actual effort together. A record of 180 kg for five is incomplete. A record of 180 kg for five at RPE 9 explains why repeating or reducing that load may be more appropriate than automatically adding weight.

This is the main benefit of using a dedicated training log: it reduces the work required to connect the prescription, performance, and next decision. It does not remove athlete judgment. See the available workflow on the LiftnLog features page, or use the RPE calculator for powerlifting when you need an estimated load or one-rep max from a completed set.

Common RPE and RIR mistakes in strength training

The most common error is rating discomfort instead of remaining performance. High-repetition squats can feel severe while several reps remain. A heavy single may feel psychologically demanding even though bar speed and position indicate clear reserve.

Another error is changing the definition of an acceptable rep. If a lifter counts a shallow squat as reserve capacity on one week but requires competition depth the next, the ratings cannot be compared. Set the technical standard before the work set.

Lifters also tend to rate the plan rather than the set. If the program says RPE 8, there is pressure to enter RPE 8 after completing the prescribed load. Record what happened. An overshoot is training information, not a moral failure.

Do not adjust loads after every half-point difference. If a first back-off set lands at RPE 7.5 instead of 8, the original load may still be correct. Plate availability, normal uncertainty, and changing fatigue make tiny corrections noisy. Adjust when the miss is clear or when later sets confirm a pattern.

The opposite failure mode is refusing to adjust because the percentage is written in the program. Percentages describe expected loading. RPE and RIR describe current capability. If 80% produces RPE 9 when the target was RPE 7, completing all planned work unchanged defeats the purpose of autoregulation.

Finally, avoid using estimated one-rep max as a daily scorecard. An estimate derived from an RPE-rated set inherits any error in that rating. Compare estimates over several exposures under similar conditions. The broader powerlifting autoregulation guide covers when a set-level adjustment should lead to a program-level change.

Should you use RPE or RIR for powerlifting?

Use RPE when the program already prescribes a 1-to-10 effort target, when half-point distinctions affect loading, or when coaches and athletes share established RPE language. It is especially practical for top singles and top sets where RPE 8, 8.5, and 9 can lead to different decisions.

Use RIR when direct wording improves clarity. “Stop with two good reps remaining” is often easier for a beginner to apply than “work at RPE 8.” RIR also works well for accessory training, where the main concern is staying a defined distance from failure.

There is no need to record both values for every set if they are simple conversions. Pick one scale, define it clearly, and keep the other as a translation tool. Preserve prescribed and actual effort as separate fields or notes.

For powerlifters already working from RPE-based programming, staying with RPE usually creates the cleanest long-term record. Lifters following an RIR prescription should not convert everything merely to make the log look more advanced. Reliable entries are more valuable than extra notation.

RPE vs RIR FAQ

Is RPE 8 the same as two reps in reserve?

Yes, under the powerlifting-specific RPE scale. RPE 8 means the lifter estimates that two additional technically acceptable reps were available. It remains an estimate, so RPE 8 should not be interpreted as a laboratory measurement.

Is three RIR equal to RPE 7?

Yes. Subtract RIR from 10, which gives RPE 7. This conversion is most useful when sets are reasonably close to failure. At five or more RIR, precise conversion adds little practical value.

Should I rate RPE after every set?

Rate work sets when the result can affect loading, progression, or future programming. Warm-up sets do not always need formal ratings, although an unexpectedly difficult warm-up should influence the planned top set. Recording every trivial set can create more data without improving decisions.

Can bar speed tell me my RPE or RIR?

Bar speed provides supporting evidence, especially when you have video or velocity data from comparable sets. It does not perfectly determine reserve repetitions. Technique, exercise variation, fatigue, and individual lifting style all affect how speed changes near failure. Assign the rating from the completed set, then use speed as a check.

What if my RPE ratings are always wrong?

Compare immediate ratings with video and later performance. Use safe exercises to experience sets at zero, one, and two RIR, then apply those reference points to competition lifts. Keep the same technical standard each time. Accuracy normally improves through repeated calibration, not by adding more decimal places.

Should beginners use RPE or percentage-based training?

Beginners can use both. Percentages provide structure, while broad RPE limits prevent a fixed load from becoming inappropriate on a difficult day. Early programming might prescribe a percentage range with a cap such as RPE 7 or 8. Exact half-point targets are usually unnecessary until the lifter can judge reserve repetitions consistently.

Does RPE 10 mean I failed the lift?

No. RPE 10 means no additional acceptable repetition was available. A successfully completed maximal single can be RPE 10. A failed lift does not receive a normal completed-set rating because the prescribed repetition was not finished.

Which scale should I enter in my training log?

Enter the scale used by the program. If the plan says RPE 8, record actual RPE. If it says two RIR, record actual RIR. Add the other scale only when a coach, athlete, or software workflow needs the conversion. For lifters who want prescription and performance kept together, LiftnLog provides a focused place to maintain that record.