Free RPE calculator

This RPE calculator turns one hard set into two useful numbers: an estimated one rep max, and the weight to load for the next set you have planned. It uses the Tuchscherer RPE chart from Reactive Training Systems, a widely shared table that links reps and effort to a percentage of your max. Everything on this page is compiled from published research and coaching sources, listed at the bottom.

How to use the RPE calculator

Enter one set you just finished, then the set you want to do next. The calculator does the rest and updates as you type.

1. Pick your units. Choose lb or kg. The suggested weight rounds to 5 lb or 2.5 kg jumps: a 2.5 lb or 1.25 kg plate on each side.
2. Enter the set you did. Type the total weight on the bar, including the bar. Choose the reps you finished (1 to 10) and how hard the set felt on the RPE scale (6.5 to 10).
3. Enter the set you want to do. Choose your target reps and target RPE, for example 3 reps at RPE 8.
4. Read the results. You get your estimated 1RM, a suggested weight for the target set, and a small table with loads for your target reps at every RPE from 6.5 to 10.

The page address updates with your inputs, so you can bookmark or share a result.

What is RPE in lifting?

RPE in lifting is a 1 to 10 rating of how hard a set was, based on how many more reps you could have done. RPE stands for rate of perceived exertion. Mike Tuchscherer of Reactive Training Systems describes it as “a measure of difficulty for the previous set,” where 10 is the hardest set you can complete.

The older Borg RPE scale came from cardio research and asked how hard exercise felt overall. Lifters found it vague. In 2016, Michael Zourdos and colleagues published a lifting-specific version in the Journal of Strength and Conditioning Research. On their scale, each number maps to reps in reserve: RPE 10 means no reps left, RPE 9 means one rep left, and so on.

RIR (reps in reserve) is the number of clean reps you could still have done when you racked the bar. That is the key idea behind the modern RPE scale. You are not rating sweat or mood. You are estimating how close you were to failure.

RPE scale and RIR chart

The RPE scale and the RIR chart are the same thing seen from two sides. The table below follows the scale described by Zourdos and colleagues (2016) and explained by Helms and colleagues in the Strength and Conditioning Journal (2016). The half-step wording for 9.5 and 8.5 comes from the 2018 Helms study.

RPE	Reps in reserve (RIR)	What it means
10	0	Max effort. No more reps were possible.
9.5	0	No more reps, but you could have added a little weight.
9	1	One more rep was possible.
8.5	1 to 2	One more rep for sure, maybe two.
8	2	Two more reps were possible.
7.5	2 to 3	Two more reps for sure, maybe three.
7	3	Three more reps were possible.
5 to 6	4 to 6	Four to six reps left. A moderate set.
3 to 4	Not counted	Light effort.
1 to 2	Not counted	Little to no effort.

Helms and colleagues explain why the scale stops counting reps below RPE 5. People estimate reps left more accurately when a set is close to failure, and it is easier to give a range once more than three reps are left. So the scale groups 5 and 6 together as “4 to 6 reps left” and uses plain effort words below that.

The calculator accepts RPE 6.5 because it appears on the Tuchscherer percentage chart. It is not a separate step on the Zourdos scale. Treat 6.5 as roughly three to four reps left.

What does RPE 8 mean?

RPE 8 means you finished the set with about two good reps left. It is hard work, but you could have kept going with clean form. Many programs use RPE 8 for main working sets because it is heavy enough to drive progress while leaving room for error.

What does RPE 10 mean?

RPE 10 means a true max effort: you could not have done one more rep at that weight. Tuchscherer is clear that the set still counts as completed. A missed rep is not RPE 10; it is a failed set.

What does RPE 9.5 mean?

RPE 9.5 means no more reps were possible, but the bar would have moved with a little more weight. It often shows up on heavy singles, where you know a slightly heavier attempt would have gone up.

RPE to percentage chart

The RPE to percentage chart links reps and RPE to a percentage of your one rep max. The numbers below are the Tuchscherer (Reactive Training Systems) chart, as reproduced by Fitness Volt. Find your reps on the left and your RPE across the top.

Reps	RPE 10	RPE 9.5	RPE 9	RPE 8.5	RPE 8	RPE 7.5	RPE 7	RPE 6.5
1	100%	97.8%	95.5%	93.9%	92.2%	90.7%	89.2%	87.8%
2	95.5%	93.9%	92.2%	90.7%	89.2%	87.8%	86.3%	85.0%
3	92.2%	90.7%	89.2%	87.8%	86.3%	85.0%	83.7%	82.4%
4	89.2%	87.8%	86.3%	85.0%	83.7%	82.4%	81.1%	79.9%
5	86.3%	85.0%	83.7%	82.4%	81.1%	79.9%	78.6%	77.4%
6	83.7%	82.4%	81.1%	79.9%	78.6%	77.4%	76.2%	75.1%
7	81.1%	79.9%	78.6%	77.4%	76.2%	75.1%	73.9%	72.3%
8	78.6%	77.4%	76.2%	75.1%	73.9%	72.3%	70.7%	69.4%
9	76.2%	75.1%	73.9%	72.3%	70.7%	69.4%	68.0%	66.7%
10	73.9%	72.3%	70.7%	69.4%	68.0%	66.7%	65.3%	64.0%

Look at the diagonal pattern. Five reps at RPE 8 is 81.1%. So is 6 reps at RPE 9 and 7 reps at RPE 10. All three describe the same thing: a weight you could lift about 7 times at most. That is the logic of the whole chart. Each rep you do, and each rep you leave in reserve, counts the same.

Why this chart stops at 10 reps and RPE 6.5

The chart above covers 1 to 10 reps and RPE 6.5 to 10 because those are the values the source table shows. Other websites publish versions that go to RPE 6 or 12 reps, but their numbers do not match each other past this range. Rather than print numbers that cannot be traced to one source, this page and the calculator stay inside the published grid.

There is also a practical reason. Halperin and colleagues’ 2022 meta-analysis found that people predict reps to failure less accurately on sets longer than 12 reps. Helms and colleagues note that ratings are less accurate far from failure. Low-RPE, high-rep sets are where any chart is weakest.

How the RPE calculator works

The RPE calculator uses two simple steps: divide to estimate your max, then multiply to find your next weight.

Step 1: estimated 1RM. Look up the percentage for the set you did, then divide the weight by it.

Estimated 1RM = weight lifted ÷ (chart percentage ÷ 100)

Step 2: suggested weight. Look up the percentage for the set you want, then multiply.

Suggested weight = estimated 1RM × (target percentage ÷ 100)

The calculator then rounds the suggested weight to the nearest 5 lb or 2.5 kg, so you can actually load it.

Worked example in pounds

Say you squatted 225 lb for 5 reps, and it felt like RPE 8. You want to do triples at RPE 8 next week.

• 5 reps at RPE 8 is 81.1% on the chart.
• Estimated 1RM = 225 ÷ 0.811 = 277.4 lb.
• 3 reps at RPE 8 is 86.3% on the chart.
• Suggested weight = 277.4 × 0.863 = 239.4 lb, which rounds to 240 lb.

Worked example in kilograms

Say you bench pressed 100 kg for 5 reps at RPE 8, and you want 3 reps at RPE 8.

• Estimated 1RM = 100 ÷ 0.811 = 123.3 kg.
• Suggested weight = 123.3 × 0.863 = 106.4 kg, which rounds to 107.5 kg.

Worked example: a heavy single

Say you deadlifted 315 lb for 8 reps at RPE 8, and you want to know what a single at RPE 9 might look like.

• 8 reps at RPE 8 is 73.9%, so the estimated 1RM is 315 ÷ 0.739 = 426.3 lb.
• 1 rep at RPE 9 is 95.5%, so the suggested single is 426.3 × 0.955 = 407.1 lb, which rounds to 405 lb.

Treat big jumps like this with care. A set of 8 is a long way from a heavy single, so work up in steps.

How to use RPE in lifting

To use RPE, you pick a target, lift, rate the set honestly, and adjust the weight for the next set. It takes a few weeks of practice to rate sets well.

A typical RPE workout looks like this:

1. Get a target from your program. For example, 3 sets of 5 at RPE 8.
2. Choose a starting weight. Use this calculator with a recent set, or use last week’s weight.
3. Do the first set and rate it. Ask one question: how many more clean reps could I have done?
4. Adjust. If the set felt like RPE 9, drop the weight a little. If it felt like RPE 7, add a little.
5. Log it. Write down weight, reps and RPE every time. The log is what makes your future estimates better.

Tuchscherer’s advice is to keep target weights in your plan but let RPE “fine-tune that weight up or down based on how you’re performing.” RPE is a steering wheel, not a replacement for a plan.

How much to change the weight

The 2018 Helms study gives one concrete example of how to adjust. When a set came in above the target range, the load dropped by 2% for every half point over. When it came in below the range, the load went up. The table below shows their example for a target range of RPE 6 to 8.

Actual RPE	Change to the next set (target RPE 6 to 8)
10	Decrease load by 8%
9.5	Decrease load by 6%
9	Decrease load by 4%
8.5	Decrease load by 2%
6 to 8	Lifter’s choice
5	Increase load by 4%
4	Increase load by 8%
3	Increase load by 12%

That was the rule in one study, not a law. The calculator does the same job a different way: it rebuilds your estimated max from each set and hands you a new load.

What is autoregulation in lifting?

Autoregulation means letting your performance on the day set the weight, instead of a fixed number written weeks ago. RPE is the most common way to do it. Tuchscherer puts it simply: RPE “lets the load adjust to fit your performance.”

Strength changes from day to day. Helms and colleagues point out that sleep, stress and fatigue from earlier training can all move your numbers. They also note that a 1RM “is not stable in novice populations,” since new lifters get stronger quickly. A percentage based on an old max can end up too light or too heavy.

With autoregulation, a good day lets you use more weight and a rough day lets you back off, while the effort stays about the same.

RPE vs percentage training

RPE training sets the weight by effort, while percentage training sets it from a fixed share of a tested max. Both work, and research so far shows no big winner.

In 2018, Eric Helms and colleagues ran an eight-week study with 21 trained men who squatted and bench pressed three times a week. Both groups did the same sets and reps. One group used percentages of their tested max. The other used RPE targets. Both groups got stronger. The RPE group gained 17.1 kg on the squat and 10.7 kg on the bench, compared with 13.9 kg and 9.6 kg in the percentage group, but the difference was not statistically significant. The authors concluded that “both loading-types are effective,” with a possible small strength edge for RPE-based loading in most people. The RPE group also trained at a higher average effort.

	Percentage training	RPE training
How weight is set	Fixed % of a tested max	Effort on the day
Needs a tested 1RM	Yes	No, though an estimate helps
Adapts to a bad day	No	Yes
Easy for beginners	Yes, numbers are clear	Harder, rating takes practice
Main risk	Max goes stale, loads drift	Rating sets too easy or too hard

A blend often works best. Helms and colleagues suggest you can prescribe a percentage and add an RIR target, such as 3 sets of 3 at 90% with 0 to 1 reps left. If the percentage feels too easy or too hard, the RPE tells you which way to adjust.

Is RPE accurate for beginners?

RPE is less accurate for beginners, and it gets better with practice. That is the clearest finding across the research.

• Zourdos and colleagues (2016) compared experienced squatters, with about five years of training, to novices with under a year. On a true 1RM, experienced lifters rated it close to 10 (an average of 9.80). Novices rated the same max effort lower (8.96).
• Steele and colleagues (2017) asked 141 people to predict how many reps they could do before failure. Most people underpredicted, and accuracy tended to improve with more training experience.
• Halperin and colleagues (2022) pooled 12 studies with 414 participants. On average, people underpredicted their reps to failure by about one rep (0.95). Predictions were better closer to failure, with heavier loads and in later sets. In this larger review, training background did not clearly change accuracy.

Helms and colleagues give practical advice: “novice lifters should practice recording RIR, but likely not base training intensity or progression solely on the RIR-based scale until increased accuracy is achieved.” They suggest a simple check. Rate a submaximal set, then do another set with the same weight to failure and see if your guess was right. For a home lifter training alone, only do that check on lifts where failing is safe, such as a bench press inside a rack with safety arms set, or on machines and dumbbells.

If you are new, use this calculator for a rough starting weight, keep sets around RPE 7 to 8, and log your ratings. Your estimates will sharpen.

What RPE should I train at?

Most working sets in RPE-based programs sit between RPE 6 and 9, with RPE 10 used sparingly. The right range depends on your goal and where you are in a training block.

The 2018 Helms study shows one real example. Over eight weeks, the RPE group moved from sets at RPE 5 to 7 in week one, to 6 to 8, then 7 to 9, then 8 to 10 in weeks six and seven, before easing back to 6 to 8. Reps dropped as effort went up, from sets of 8 early on to sets of 2 near the end.

Helms and colleagues suggest the RIR-based scale is most useful for sets taken near failure or a few reps short of it (RPE 7 to 10). They advise against relying on it for light, fast power work under about 80% of max, where rating reps left is hard to do well.

How to read and act on your result

Your estimated 1RM is a planning number, not a new personal record. Use it to choose weights, then let the bar confirm them.

• Use recent sets. A set from today tells you more than one from last month.
• Prefer lower-rep sets. Reps-left guesses are more accurate on shorter, heavier sets, so estimates from them carry less error.
• Average a few results. If three sets this week give estimates of 270, 277 and 281 lb, plan around the middle.
• Round down when unsure. If the suggested weight lands between plates, pick the lighter option on your first set and adjust from there.
• Compare lifters fairly. To compare strength across body weights, put your estimated max into the DOTS calculator.
• Load the bar. Use the barbell calculator to see which plates to put on each side.

If you want a max estimate from a set taken to failure, the one rep max calculator uses classic formulas instead of RPE.

Accuracy limits and who the chart does not fit

The Tuchscherer chart is an average, and your own numbers may differ. Treat every result as a starting guess.

• It was built around the powerlifts. Tuchscherer suggests lifters “develop a chart for each lift,” since each lift can have different percentages. He expects many lifters to end up with three charts that look different.
• People differ in rep strength. Helms and colleagues note large differences in how many reps people can do at the same percentage. In the Zourdos data, a set of 8 at 70% drew ratings ranging from roughly 2 to 4 reps left for most lifters, and as wide as 1 to 5 for some.
• Beginners rate less accurately, as covered above.
• High reps are less reliable. Accuracy drops on longer sets, so a max estimated from 10 reps carries more error than one from 3.
• Other published charts differ. Some calculators round the numbers or extend them with a formula. Expect results to differ by a few percentage points between tools, most of all at high reps.

The chart fits poorly for lifters coming back from injury and for anyone who has not yet learned to judge reps left.

Common RPE mistakes

Most RPE mistakes come from rating the wrong thing. Here are the ones coaches and researchers flag most.

• Rating how you feel, not reps left. Tuchscherer warns that RPE is “about your exertion relative to a maximum effort,” not your mood. A set can feel awful and still be RPE 7.
• Sandbagging. The research shows people tend to underpredict how many reps they have left. If every set is “RPE 9,” test a few with a spotter or safeties.
• Chasing RPE 10 every session. Max efforts cost a lot of recovery and carry more risk, most of all when training alone.
• Changing the weight too much. In the 2018 Helms study, loads moved just 2% for each half point off target. Big swings make your log hard to read.
• Not logging RPE. Without notes, you cannot check your ratings or spot trends over weeks.
• Trusting a far-off estimate. A max estimated from a set of 10 should not guide a heavy single without warm-up steps in between.

Using RPE in kilograms

RPE percentages work the same in kilograms and pounds, because they are shares of your own max. Only the rounding changes.

The calculator rounds kilogram loads to 2.5 kg, which is a 1.25 kg plate on each side. If you want finer steps, fractional or change plates let you add less. See the guide to the best change plates for options. Pound users get 5 lb steps, which is a 2.5 lb plate per side.

RPE training in a home gym

RPE suits home training well, because it lets you adjust without a coach watching. It also asks you to be honest about safety, because most home lifters train alone.

A few home gym points matter when you train by RPE:

• Set your safeties for every heavy squat and bench. A power rack with safety arms or straps lets you miss a rep safely. The guide on how to use a power rack for squats covers setting the height, and what is a power rack explains the parts.
• Add spotter arms to open racks. If you train on a half rack or squat stands, spotter arms give you a way to dump a failed rep. Compare setups in squat rack vs power cage.
• Keep RPE 9.5 and 10 for set-ups where failing is safe. Alone in a garage, a missed bench without safeties is a real danger.
• Own enough plate steps. RPE adjustments are small, so you need plates that allow 5 lb or 2.5 kg jumps. Calibrated weight plates and change plates help here.

If you are still choosing a rack, the best power racks guide compares options for home use.

Safety

RPE training asks you to work close to failure, so safety comes first. Warm up with lighter sets before heavy work. Keep good form as the priority: if your technique breaks down, the set is over, whatever the number says. Set safety arms or straps at the right height for squats and bench presses, and use a spotter when you can. Sets at RPE 9.5 and 10 carry the most risk, most of all when you train alone.

This page is general information, not personal coaching or medical advice. If you have an injury, a health condition or pain during lifting, talk to a doctor or a qualified coach before training close to failure.