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RPE calculator and chart

Enter a set you’ve done to estimate your one-rep max, then pick the reps and RPE for your next set to get the weight to load. The full chart, with reps in reserve, is below.

Your set

Estimated one-rep max123.3 kgEpley’s formula, which ignores RPE: 116.7 kg

Next set

Weight to load110 kgExactly 110 kg, rounded to the nearest 2.5 kg

RPE chart: percentage of your one-rep max

Find your reps on the left and your RPE across the top. The cell is the share of your max that set uses. Under each RPE is how many good reps were left, as Arclift’s RPE keypad puts it. The calculator marks your set in blue and the next set in dark blue.

RepsRPE 10MaxRPE 9.50 leftRPE 91 leftRPE 8.51–2 leftRPE 82 leftRPE 7.52–3 leftRPE 73 leftRPE 6.53–4 left
1100.0%97.8%95.5%93.9%92.2%90.7%89.2%87.8%
295.5%93.9%92.2%90.7%89.2%87.8%86.3%85.0%
392.2%90.7%89.2%87.8%86.3%85.0%83.7%82.4%
489.2%87.8%86.3%85.0%83.7%82.4%81.1%79.9%
586.3%85.0%83.7%82.4%81.1%79.9%78.6%77.4%
683.7%82.4%81.1%79.9%78.6%77.4%76.2%75.1%
781.1%79.9%78.6%77.4%76.2%75.1%73.9%72.3%
878.6%77.4%76.2%75.1%73.9%72.3%70.7%69.4%
976.2%75.1%73.9%72.3%70.7%69.4%68.0%66.7%
1073.9%72.3%70.7%69.4%68.0%66.7%65.3%64.0%
1170.7%69.4%68.0%66.7%65.3%64.0%62.6%61.3%
1268.0%66.7%65.3%64.0%62.6%61.3%59.9%58.6%

Percentages from Mike Tuchscherer’s RPE chart (Reactive Training Systems), as commonly published. The reps-in-reserve scale behind it was tested by Zourdos and colleagues in the Journal of Strength and Conditioning Research (2016).

What RPE means in the gym

RPE stands for rating of perceived exertion. Gunnar Borg’s original scale rated how hard any exercise felt. For lifting, coach Mike Tuchscherer reframed it around one question you can answer after every set: how many more good reps could you have done? A 2016 study by Michael Zourdos and colleagues tested that version, tying each point on the scale to reps in reserve, and it is the scale most strength programs use today.

On that scale, RPE 10 means nothing was left: no more reps and no more weight. RPE 9 means one more good rep, RPE 8 two, RPE 7 three. The half points cover the sets in between: 9.5 means you couldn’t have done another rep but could have added a little weight, and 8.5 means one more rep for sure and maybe two.

RPE and RIR are the same scale

Reps in reserve (RIR) counts the same thing from the other end. RPE 8 is 2 RIR, RPE 9 is 1 RIR and RPE 10 is 0 RIR, so a program written in either language translates directly: subtract the RIR from 10 to get the RPE. The chart’s headings show both.

How to read the chart

Five reps at RPE 8 is 81.1%. If your best single is 140 kg, a set of 5 at RPE 8 should land near 113.5 kg, which you would load as 112.5 kg.

It works backwards too, and that is what the calculator does. Divide the weight you lifted by the percentage and you get an estimated max: 100 kg for 5 reps at RPE 8 is 100 ÷ 0.811, about 123 kg. From there, any other cell gives a working weight. Three reps at RPE 9 is 89.2% of 123 kg, about 110 kg.

Using RPE to pick today’s weight

A percentage written months ago assumes you are exactly as strong as you were then. RPE lets the day decide. Take your first work set at the weight the chart suggests, rate it honestly, and adjust: if a set you planned at RPE 8 felt like a 9, take a little off the next one; if it felt like a 7, add a little.

Two cautions. Ratings get more accurate with practice, so treat early ones as rough. And the chart is least reliable on long sets: an estimate from 10 or 12 reps can miss your real max by more than one from 3 to 5 reps, so estimate from heavier sets and train with the lighter ones.

How Arclift handles RPE

Arclift’s RPE keypad asking how many good reps were left, with values from 6 to 10.
Arclift’s RPE keypad, with the reps left under each value.

Arclift has an RPE field on every set it logs. It opens its own keypad that asks how many good reps were left, in the same half-point steps as this chart, and you can switch it off in settings if you never rate effort.

With Arclift Pro, the progression coach reads those ratings: a set logged at low effort earns a bigger jump next time, and a near-maximal one holds the weight. Warmup and drop sets never count toward progression targets, so a heavy-feeling warmup can’t skew them.

Arclift’s Est. 1RM metric uses Epley’s formula on your top set, weight × (1 + reps ÷ 30). That is why the calculator shows the Epley number too: it ignores RPE, so for sets that stop short of failure it usually reads lower than the chart.

Questions

What does RPE 8 mean?

RPE 8 means you finished the set with about two good reps left: you could have done two more with the same weight and technique, but not three. On the chart, 5 reps at RPE 8 is 81.1% of your one-rep max.

How do you calculate a one-rep max from RPE?

Look up your reps and RPE on the chart to get a percentage, then divide the weight by it. 100 kg for 5 reps at RPE 8 is 100 ÷ 0.811, so your estimated max is about 123 kg. The calculator above does this for any set from 1 to 12 reps.

Is RPE the same as RIR?

They describe the same thing from opposite ends. RIR counts the good reps you had left, and RPE is 10 minus that number, so RPE 8 is 2 RIR and RPE 10 is 0 RIR. Half points such as 8.5 sit between two RIR values.

What RPE should I train at?

It depends on the program, but many keep most work sets between RPE 7 and 9 and save RPE 10 for tests or the last set of an exercise. If you are new to rating effort, aim a little lower until your ratings settle.

Why does the chart stop at 12 reps and RPE 6.5?

That is the range the chart was published for. Further from failure than RPE 6.5, effort is hard to rate precisely, and beyond 12 reps small rating errors move the estimate a lot, so numbers outside the chart would look more exact than they are.

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Log RPE on every set.

Arclift has an RPE keypad on every set and, with Pro, a progression coach that uses those ratings to set your next weight. Logging is free.

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