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RPE Calculator (RPE and RIR Chart)
Written by the GymStreak coaching teamUpdated
A set you just did
The set you want to do
RPE 10 means you could not have done another rep; RPE 8 means about 2 reps were left in the tank. Be honest: most people underestimate how many reps they had left.
The short answer
RPE (rate of perceived exertion) scores a set by how many reps you had left: RPE 10 means none, RPE 9 means one, RPE 8 means two, so reps in reserve (RIR) = 10 − RPE. To find a weight, treat the set as if you’d gone to failure (reps + RIR) and use a one-rep-max formula. 100 kg for 5 reps at RPE 8 counts as 7 reps to failure, an estimated max of about 121 kg, so 3 reps at RPE 8 is about 107.5 kg.
01 / How it works
How the rpe calculator works
Programmes often say "5 reps at RPE 8" instead of a fixed weight. That means: pick a load where 5 reps leaves about 2 more in the tank. This calculator does the arithmetic behind it. Give it one set you have done (weight, reps and how hard it felt) and a set you want to do, and it returns the weight for that target.
It uses the reps-in-reserve version of the RPE scale, where RPE 10 is a set you could not have continued, RPE 9 leaves one rep, RPE 8 two, and half points mean "maybe one more". Your set is treated as if you had gone to failure: 5 reps with 2 left is a 7-rep max. The calculator feeds that into the same three formulas as our one rep max calculator (Epley, Brzycki and Lander, averaged), so a set at RPE 10 gives exactly the same estimate there and here.
From that estimated max it works out the load for your target reps and RPE, rounded to the nearest 2.5 kg or 5 lb, and builds your own RPE chart for 1 to 10 reps at RPE 10, 9, 8 and 7.
02 / Formula
The RPE formulas
RPE and reps in reserve
RIR = 10 − RPE Reps to failure = reps done + RIR
- RPE = rating on the 1-10 reps-in-reserve scale (half points allowed)
- RIR = reps in reserve, the reps you could still have done
The scale was published for lifting by Zourdos and colleagues in 2016; Helms and colleagues explain how to use it to set loads.
Estimated 1RM from the set
e1RM = average of Epley: w × (1 + n ÷ 30) Brzycki: w × 36 ÷ (37 − n) Lander: 100 × w ÷ (101.3 − 2.67123 × n) with n = reps to failure (1 rep to failure = the weight itself)
- w = weight lifted (kg or lb; the answer comes out in the same unit)
These are the formulas on our one rep max calculator, with sources there.
Load for a target set
Load = e1RM ÷ (the same average multiplier for target reps + target RIR)
Reps plus reps in reserve is capped at 12: past about 10-12 reps the formulas disagree too much to be useful.
03 / Worked example
Worked examples
100 kg × 5 at RPE 8, then a triple at RPE 8
You squat 100 kg for 5 reps and think you had 2 left (RPE 8). Next week calls for 3 reps at RPE 8.
- 1Reps to failure: 5 + 2 = 7
- 2Epley 123.3 kg, Brzycki 120.0 kg, Lander 121.1 kg
- 3Estimated 1RM: average ≈ 121.5 kg
- 4Target 3 at RPE 8 = 5 reps to failure → 87.5% of the max
- 5121.5 × 0.875 = 106.3 kg → nearest 2.5 kg = 107.5 kg
Load the bar to about 107.5 kg for the triple.
225 lb × 8 at RPE 9, then 5 reps at RPE 8
You bench 225 lb for 8 reps with one rep left (RPE 9) and want a set of 5 at RPE 8.
- 1Reps to failure: 8 + 1 = 9
- 2Estimated 1RM: average of 292.5, 289.3 and 291.2 ≈ 291 lb
- 3Target 5 at RPE 8 = 7 reps to failure → 82.3%
- 4291 × 0.823 = 239.6 lb → nearest 5 lb = 240 lb
Use about 240 lb for the set of 5.
04 / Reference
RPE charts and tables
| Reps | RPE 10 | RPE 9.5 | RPE 9 | RPE 8.5 | RPE 8 | RPE 7.5 | RPE 7 | RPE 6.5 |
|---|---|---|---|---|---|---|---|---|
| 1 | 100% | 97.0% | 95.6% | 94.2% | 92.9% | 91.5% | 90.1% | 88.8% |
| 2 | 95.6% | 94.2% | 92.9% | 91.5% | 90.1% | 88.8% | 87.5% | 86.2% |
| 3 | 92.9% | 91.5% | 90.1% | 88.8% | 87.5% | 86.2% | 84.9% | 83.6% |
| 4 | 90.1% | 88.8% | 87.5% | 86.2% | 84.9% | 83.6% | 82.3% | 81.1% |
| 5 | 87.5% | 86.2% | 84.9% | 83.6% | 82.3% | 81.1% | 79.8% | 78.6% |
| 6 | 84.9% | 83.6% | 82.3% | 81.1% | 79.8% | 78.6% | 77.3% | 76.1% |
| 7 | 82.3% | 81.1% | 79.8% | 78.6% | 77.3% | 76.1% | 74.9% | 73.6% |
| 8 | 79.8% | 78.6% | 77.3% | 76.1% | 74.9% | 73.6% | 72.4% | 71.2% |
| 9 | 77.3% | 76.1% | 74.9% | 73.6% | 72.4% | 71.2% | 70.0% | – |
| 10 | 74.9% | 73.6% | 72.4% | 71.2% | 70.0% | – | – | – |
Computed with this calculator's method (reps + RIR into the averaged Epley, Brzycki and Lander formulas). A dash means reps + RIR would pass 12. Coach-made charts, such as the widely shared RTS chart, differ from this by a few percent in places; no chart fits every lifter or every lift.
| RPE | Reps in reserve | What it feels like |
|---|---|---|
| 10 | 0 | Could not have done another rep |
| 9.5 | 0–1 | Maybe one more rep, not sure |
| 9 | 1 | One more rep for sure |
| 8.5 | 1–2 | One more for sure, maybe two |
| 8 | 2 | Two more reps left |
| 7 | 3 | Three left; the bar still moves fast |
| 6 | 4 | Four or more left; a hard warm-up |
05 / Training
How to use RPE in your training
- Use the result as a starting weight, then let the set decide. If the first set of "5 at RPE 8" feels like RPE 9, take a little off the next one. That self-correction is the point of RPE.
- Most working sets sit around RPE 7 to 9 (1 to 3 reps in reserve). Research summaries find sets taken close to failure build muscle about as well as sets taken all the way, with less fatigue. See should you be training to failure? and how hard should you be training?.
- Rate the set straight after the last rep, before you rack the weight and the feeling fades. In studies, ratings were more accurate in experienced lifters and on sets that ended close to failure.
- New to the terms? Read the plain-English pages on RPE and reps in reserve. To plan when to add weight, use the progressive overload calculator.
06 / Limitations
Limitations and safety
Every number here is an estimate built on two estimates: how many reps you really had left, and a one-rep-max formula. People, especially beginners, tend to underestimate how many reps they had left, which makes the calculated loads come out low.
The formulas fit sets of up to about 10 reps best and vary between lifts and people; many lifters do more reps at a given percentage on the leg press than on the bench press. Treat the chart as a guide and adjust from how the bar moves.
Warm up before heavy sets, use safety bars or a spotter, and never chase a number with poor technique.
This calculator gives an estimate for general fitness education. It is not medical advice and does not diagnose anything. If you have a health condition, are pregnant, or are new to hard exercise, check with a doctor first.
07 / FAQ
Frequently asked questions
What does RPE mean in lifting?
RPE stands for rate of perceived exertion. In lifting it scores a set from 1 to 10 by how many reps you had left: RPE 10 means you could not do another rep, RPE 9 means one more, RPE 8 means two more.
How do you convert RPE to RIR?
Subtract the RPE from 10: reps in reserve = 10 − RPE. RPE 8 is 2 reps in reserve, RPE 7 is 3, and RPE 8.5 means one or two reps left.
What percentage of 1RM is 5 reps at RPE 8?
About 82%. Five reps with two left is like a 7-rep max, and the averaged Epley, Brzycki and Lander formulas put a 7-rep max at about 82.3% of a one-rep max. Other charts give 81 to 83%.
How do I calculate weight from RPE?
Estimate your max first, from a recent set: add your reps and reps in reserve, and use a one-rep-max formula on that many reps. Then multiply the max by the percentage for your target reps and RPE from the chart. The calculator does both steps and rounds to a loadable weight.
What RPE should I train at?
Most working sets for muscle and strength land around RPE 7 to 9, leaving one to three reps in reserve. Lighter or technique work can sit lower; going to RPE 10 now and then is fine but adds fatigue.
Is RPE the same as RIR?
They measure the same thing from opposite ends. RIR counts the reps left, RPE scores the effort out of 10, and RPE = 10 − RIR on this scale.
Sources
- Helms ER, Cronin J, Storey A, Zourdos MC. Application of the repetitions in reserve-based rating of perceived exertion scale for resistance training. Strength Cond J. 2016;38(4):42-49.
- Zourdos MC, Klemp A, Dolan C, et al. Novel resistance training-specific rating of perceived exertion scale measuring repetitions in reserve. J Strength Cond Res. 2016;30(1):267-275.
- Epley B. Poundage Chart. Boyd Epley Workout. Lincoln, NE: Body Enterprises; 1985.
- Brzycki M. Strength testing: predicting a one-rep max from reps-to-fatigue. J Phys Educ Recreat Dance. 1993;64(1):88-90.
- Lander J. Maximum based on reps. NSCA Journal. 1985;6:60-61.
Related tools
- One Rep Max CalculatorEstimate your 1RM from any set of 1–12 reps and get training loads for every percentage.
- Progressive Overload CalculatorEnter today’s sets and a rep range to get next session’s weight and reps by double progression.
- Strength Level CalculatorStrength standards by body weight: see how your bench, squat, deadlift and overhead press compare with your body weight, and your next milestone.
From the blog
Exercises to try
- Barbell SquatsBeginner compound barbell exercise for the quadriceps, also working the glutes.
- Barbell Bench PressBeginner compound barbell exercise for the chest, also working the triceps and shoulders.
- Barbell DeadliftIntermediate compound barbell exercise for the hamstrings, also working the glutes, abs and calves.
- Front Barbell SquatsIntermediate compound barbell exercise for the quadriceps, also working the glutes.
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