RPE and RIR Explained: How to Know How Hard You’re Really Training

RPE and RIR put a number on how hard a set really was. Here’s what they mean, a simple conversion chart and practical ways to use them in your training.

If you have ever seen “3x5 @ RPE 8” in a program and wondered what you were supposed to do with it, you are in good company. With RPE and RIR explained in plain terms, it comes down to this: they are two ways of describing how close a set took you to failure. They also solve a problem that fixed weights and percentages can’t, which is that you don’t walk into the gym as the same lifter every day.

What does RIR mean?

RIR stands for reps in reserve: the number of reps you could still have done, with good form, when you racked the bar. Say you squat five reps and you’re confident you had two more in you. That set was 2 RIR.

The appeal is how concrete it is. You don’t have to put a feeling into words. You just answer one question: how many more could I have done? It’s an estimate, but it’s one you can get much better at.

The “good form” part matters. If your lower back starts rounding on a deadlift or the bar stalls and drifts toward your face on the bench, those grinders don’t count as reserve. The limit is technical failure, not the last rep you could survive.

What does RPE mean?

RPE stands for rating of perceived exertion. Endurance coaches have used versions of it for decades, the best known being the Borg scale. In strength training, the version you’ll see almost everywhere is a 1–10 scale where 10 means you couldn’t have done another rep.

In practice, only the top half of the scale matters when you lift. RPE 3 is basically a warm-up. The real decisions happen between RPE 7, 8 and 9, which is why many lifters use half points like 8.5 or 9.5 once the weights get heavy.

How RPE and RIR fit together

The lifting RPE scale is built on reps in reserve. The rule of thumb is simple: RPE equals 10 minus your RIR. RPE 8 means two reps left in the tank, and 2 RIR means RPE 8. Same information, two labels.

Below roughly RPE 6, the link to RIR gets fuzzy. Telling five reps in reserve from seven is hard, and it rarely matters. Save RPE and RIR for your working sets, where the numbers actually drive what you do next.

How to rate your sets accurately

Rating effort is a skill, just like the technique of a lift. Expect your numbers to be rough for the first few weeks. That’s normal, and it gets better with practice.

Beginners often think they’re closer to failure than they are

When you’re new to lifting, a hard set feels unfamiliar. Your muscles burn, you’re breathing hard, the bar feels heavy, and it’s easy to decide you’re at zero reps in reserve when you may have had three or four left. So treat your early ratings as a little conservative, and don’t read too much into them.

That doesn’t mean you should chase failure every session. It just helps to know, so you don’t spend months stuck on weights that are lighter than they need to be. Many lifters also find their ratings get more accurate the closer a set is to failure.

Ways to sharpen your rating

• Call it right away. Pick your number the moment you rack the weight, before you start second-guessing.
• Test yourself where it’s safe. On machines, dumbbell curls or push-ups, occasionally take a set to true failure and compare it with your guess. Skip this on heavy squats and deadlifts unless you have experience and safety arms set up.
• Film your sets. When bar speed drops noticeably and your form starts to shift, you’re usually close. Video shows that better than how it felt mid-set. The AI technique analysis in TANK also scores every rep from 0 to 100 with tips, which makes it easier to see where your form starts to slip.
• Log every rating. After a few weeks, patterns show up, like the same weight dropping from RPE 9 to RPE 7.

Using RPE in your program

The most common setup is a program that lists reps and a target RPE instead of a fixed weight. You then pick the load that hits that effort on the day.

A simple example

• Squat: 3x5 @ RPE 7–8
• Bench press: 3x8 @ RPE 8
• One-arm dumbbell row: 3x10–12 @ RPE 8–9
• Biceps curl: 2x12–15 @ RPE 9–10

Notice the pattern. Big compound lifts stay a bit further from failure, while small isolation moves can go closer. Grinding out a heavy squat costs more fatigue, and carries more risk, than missing the last rep of a curl.

Top sets and back-off sets

A popular approach is to work up to one heavier top set, say 5 reps @ RPE 8, then drop the weight by a few percent for two or three back-off sets. How you feel that day decides the top set, and the rest of the session follows from it.

Bad days, good days and progress

Slept badly? Maybe 225 lb for five feels like RPE 9 instead of 8. Take a little off the bar and keep the effort where the program wants it. On a great day, add some. Coaches call this autoregulation.

Over time, the same RPE should come with heavier weights or more reps. That’s where RPE becomes a tool for progressive overload: you’re not just tracking the weight, you’re tracking the weight at a given effort.

What an RPE training log looks like

Here are four weeks of bench press as they might look in a training log:

Look at week 3. The weight didn’t move, but the effort dropped. Without RPE, that week looks like a plateau. With it, you can see you got stronger. Whether you use a notebook or an app like TANK, the key is writing RPE next to the weight and reps every single time.

RPE for circuits, running and HYROX

RIR works best for lifting sets with clear reps. For circuits, intervals and runs, RPE is more useful as a rating for a whole session or block. An easy run might sit around RPE 3–4, where you can talk in full sentences. Threshold intervals often land around 7–8, and a race or a HYROX event pushes toward 9–10 by the finish.

Common mistakes

1. Always going to RPE 10. Taking every set to failure piles up fatigue and wrecks technique. Most working sets do fine at RPE 7–9.
2. Rating your day instead of your set. RPE describes the set you just did, not how tired you feel in general.
3. Counting ugly reps as reserve. Reps where your form falls apart are not reps in reserve.
4. Comparing your RPE with someone else’s. Your RPE 8 is yours and says nothing about your training partner’s.
5. Not adjusting the weight. If the program says RPE 8 and the set came in at 9.5, the next set should be lighter, not the same.

The bottom line

RIR is how many reps you had left. RPE is the same thing on a scale up to 10. Use them to pick the right weight for the day, log them after every working set and watch how your effort changes over time. It takes a few weeks before your ratings feel reliable, but after that you have one of the most useful tools there is for training hard enough without burning yourself out.