RPE and RIR Explained: Chart, Scale and How to Use Them

RPE and RIR are two ways to rate how hard a set was. RIR is reps in reserve: how many more reps you could have done. RPE is rate of perceived exertion on a 1–10 scale. In lifting, the two are linked by one rule: RPE = 10 − RIR. So RPE 8 means 2 reps left.

Key takeaways

• RPE 10 is failure. Each point below 10 equals one more rep in reserve.
• For muscle growth, most sets fall at RPE 7–10 (0–3 RIR). For strength, RPE 6–9 (1–4 RIR).
• Each RPE point is worth roughly 2.5–3% of load.
• RPE lets the weight adjust to how you feel on the day. That is autoregulation.
• Beginners misjudge RIR by 2–4 reps, so calibrate with a few sets to true failure.

What is RPE and RIR?

RIR (reps in reserve) counts the reps you leave in the tank. Stop a set knowing you had two more, and it was 2 RIR.

RPE (rate of perceived exertion) is a 1–10 effort score. The lifting version comes from Tuchscherer and was later popularized by Helms and colleagues. It anchors each score to reps in reserve. That makes it far more precise than "that felt hard."

The RPE RIR meaning is the same idea from two angles. RIR counts what's left. RPE scores how close you came to the limit.

The RPE RIR chart

Here is the RPE RIR scale for lifting, with a description of how each level feels.

• 10: RIR 0, How the set feels True max effort; no more reps possible
• 9: RIR 1, How the set feels One more rep was possible
• 8: RIR 2, How the set feels Two left; bar speed clearly slowing
• 7: RIR 3, How the set feels Fast and solid; three left
• 5–6: RIR 4–6, How the set feels Warm-up, technique or speed work

The formula is simple:

• RPE = 10 − RIR
• RIR = 10 − RPE

Sets with more than about 4 reps in reserve don't count as hard sets. Treat them as warm-ups, technique or speed work.

Difference between RPE and RIR

In lifting, they measure the same thing. The difference is in how they're used.

• RIR is a concrete count, which makes it easier for beginners. "Stop with two reps left" is clear.
• RPE is a scale, which allows half points like 8.5. It also works for cardio and whole sessions, not just single sets.
• Coaches often program in RPE ("3 × 5 @ 8"). Lifters often think in RIR during the set.

Outside lifting, RPE is also used for whole sessions. Multiply session RPE (0–10) by minutes to get session load. For example, 60 minutes at RPE 7 equals 420 arbitrary units. RIR has no equivalent for cardio.

Using RPE to choose your load

RPE pairs well with percentages of your one-rep max. The table below is a rounded excerpt from the widely used Tuchscherer chart.

• 1: RPE 10 100%, RPE 9 96%, RPE 8 92%, RPE 7 89%
• 5: RPE 10 86%, RPE 9 84%, RPE 8 81%, RPE 7 79%
• 8: RPE 10 79%, RPE 9 76%, RPE 8 74%, RPE 7 71%

A useful shortcut: each RPE point below 10 is about one extra rep. It is also roughly 2.5–3% less load.

Worked example

Your bench press 1RM is 200 lb. The program says 5 reps at RPE 8.

• Target % = about 81% (5 reps @ RPE 8)
• Load = 200 × 0.81 = 162 lb
• Round = 160 lb

You can also run it backward. If you did 160 lb for 5 at RPE 8, your estimated max is 160 ÷ 0.81 ≈ 198 lb. For other formulas, see our guide to calculating your 1RM.

RPE RIR autoregulation

Autoregulation means letting the day's readiness set the load. Some days you sleep badly or work stress is high. On those days, the weight that felt like RPE 8 last week may feel like RPE 9.5.

With fixed percentages, you'd grind through anyway. With RPE, you lower the load to hit the target effort. On great days, you go heavier.

This makes RPE-based programs ideal for intermediates and up. They handle bad days without wrecking progress.

RPE creep as a warning sign

RPE also tracks fatigue over time. If the same load feels 1–2 RPE points harder than it used to, fatigue is building. Combined with falling reps over two sessions, that is a sign to deload.

How hard should your sets be?

Your target RPE depends on your goal.

• Muscle growth: Typical RPE 7–10, Typical RIR 0–3
• Max strength: Typical RPE 6–9, Typical RIR 1–4
• Power and speed: Typical RPE ≤ 7, Typical RIR 3+ (never grind)
• Warm-up and technique: Typical RPE 5–6, Typical RIR 4–6

Muscle growth rises as sets get closer to failure, while strength depends on it much less. Read more on training to failure. Pair your effort target with the best rep range for hypertrophy for your exercise.

How to apply this

Use these steps to start training with RPE and RIR.

• Calibrate first. Take the last set of 2–3 safe exercises to true failure. Machines and dumbbell curls work well. Note how many reps you got.
• Compare your guess. Before that set, predict your RIR at a set rep count. Most beginners are off by 2–4 reps.
• Log effort every set. Write the RPE next to weight and reps.
• Start at RPE 7–8. Use this for the first 2–4 weeks of a new program.
• Progress to RPE 8–9. Push working sets closer as technique settles.
• Adjust load in the session. If the first set is a full point above target, drop the load about 3%. If it's a point below, add about 3%.
• Use it for progression. When a set at a given load gets easier, add load or reps. That is progressive overload guided by effort.

FAQ

What is RPE and RIR?

RPE is rate of perceived exertion, a 1–10 effort scale. RIR is reps in reserve, the number of reps you could still do at the end of a set. In lifting, RPE = 10 − RIR.

What does RPE 8 mean?

RPE 8 means you stopped with about two reps left in the tank. Bar speed is clearly slowing, but form is still solid. It is a common target for both strength and hypertrophy sets.

What is the difference between RPE and RIR?

In lifting they describe the same effort from different angles. RIR counts reps left; RPE scores effort on a 10-point scale and allows half points. RPE is also used for cardio and whole sessions, while RIR is lifting-only.

How do you use an RPE RIR chart?

Find your target RPE, then read the matching RIR to know where to stop the set. Some charts also link reps and RPE to a percentage of your 1RM. For example, 5 reps at RPE 8 is about 81% of 1RM.

What is RPE autoregulation?

Autoregulation means adjusting the load each day to hit a target effort. If you're tired, the bar feels heavier, so you lower the weight to stay at your RPE. This keeps training productive on bad days and lets you push on good ones.

Sources

• Helms E, Morgan A, Valdez A. 2019. The Muscle and Strength Pyramids: Training, 2nd ed.
• Robinson ZP et al. 2024. Exploring the dose-response relationship between estimated resistance training proximity to failure, strength gain, and muscle hypertrophy. Sports Medicine. https://doi.org/10.1007/s40279-024-02069-2
• Haff GG, Triplett NT (eds.). 2016. Essentials of Strength Training and Conditioning, 4th ed. NSCA / Human Kinetics.

RPE only works if you practice rating your sets honestly. The Field Manual keeps the RPE formula and the %1RM figures on a one-page formula sheet, so you can check a target load between sets without guessing.