RPE Calculator: Train by Effort
Enter a set and how hard it felt. You get your estimated 1RM, the weight for your next set at any RPE, and a full RPE chart for your numbers.
- RPE 6 to 10 in half steps
- Load finder
- Personal RPE chart
What is RPE in lifting?
RPE stands for rate of perceived exertion. In lifting it is a score from 1 to 10 for how hard a set was. The version most lifters use is based on reps in reserve (RIR): how many more reps you could have done with good form.
- RPE 10: no reps left. You could not do another.
- RPE 9: 1 rep left.
- RPE 8: 2 reps left.
- RPE 7: 3 reps left.
- Half steps such as RPE 8.5 mean “maybe 2, definitely 1”.
This RIR-based scale was described by Zourdos and colleagues in 2016 and explained for coaches by Helms and colleagues the same year. In their study, experienced squatters rated their sets more accurately than novices, especially near max weights. So RPE takes some practice.
How does the RPE calculator work?
It adds your reps in reserve to the reps you did, then estimates your 1RM from that total with the same seven formulas as our 1RM calculator. For example, 100 kg × 5 at RPE 8 is treated like 100 kg × 7 to failure, which gives an estimated max of about 121.6 kg.
Then it works backwards. Tell it the reps and RPE you want next, and it finds the weight. It also builds a full RPE chart for your max, with rows for 1 to 10 reps and columns for RPE 6 to 10.
Use the RPE calculator after any hard set. Over a few weeks, you will learn which weights match which RPE for you, and the RPE calculator will keep your training weights in line with how strong you are on the day.
RPE chart: percentage of 1RM
This chart shows the percentage of your 1RM for each rep count and RPE, from our formula average. Multiply your max by the percentage to get the weight. The calculator above does this for you and rounds to real plates.
| Reps | RPE 10 | RPE 9.5 | RPE 9 | RPE 8.5 | RPE 8 | RPE 7.5 | RPE 7 | RPE 6.5 |
|---|---|---|---|---|---|---|---|---|
| 1 | 100.0% | 95.9% | 94.3% | 92.9% | 91.5% | 90.2% | 89.0% | 87.8% |
| 2 | 94.3% | 92.9% | 91.5% | 90.2% | 89.0% | 87.8% | 86.6% | 85.5% |
| 3 | 91.5% | 90.2% | 89.0% | 87.8% | 86.6% | 85.5% | 84.4% | 83.3% |
| 4 | 89.0% | 87.8% | 86.6% | 85.5% | 84.4% | 83.3% | 82.3% | 81.2% |
| 5 | 86.6% | 85.5% | 84.4% | 83.3% | 82.3% | 81.2% | 80.2% | 79.2% |
| 6 | 84.4% | 83.3% | 82.3% | 81.2% | 80.2% | 79.2% | 78.3% | 77.3% |
| 7 | 82.3% | 81.2% | 80.2% | 79.2% | 78.3% | 77.3% | 76.4% | 75.5% |
| 8 | 80.2% | 79.2% | 78.3% | 77.3% | 76.4% | 75.5% | 74.6% | 73.7% |
| 9 | 78.3% | 77.3% | 76.4% | 75.5% | 74.6% | 73.7% | 72.8% | 71.9% |
| 10 | 76.4% | 75.5% | 74.6% | 73.7% | 72.8% | 71.9% | 71.1% | 70.3% |
| 11 | 74.6% | 73.7% | 72.8% | 71.9% | 71.1% | 70.3% | 69.4% | 68.6% |
| 12 | 72.8% | 71.9% | 71.1% | 70.3% | 69.4% | 68.6% | 67.8% | 67.0% |
Other published RPE charts use slightly different numbers, because they come from different data. Treat any chart as a starting point, then adjust to how the bar actually moves for you.
Why use RPE instead of percentages?
Percentages assume your max is the same every day. It is not. Sleep, stress, food and last week’s training all change what you can lift. RPE lets the weight follow how you feel on the day. If 80% feels like RPE 9 today, you can drop the weight. If it feels like RPE 6, you can add some. Many lifters use both: percentages to plan, RPE to adjust.
Tips for rating RPE accurately
- Rate straight after the set, while you still remember how the last rep felt.
- Watch bar speed. When reps slow down a lot, you are close to RPE 9 or 10.
- Practice with lighter sets. Guess your RPE, then occasionally test it with an extra rep on a safe exercise.
- Be honest. Most people underrate how many reps they had left early on.
More tools
Read our guide to RPE and RIR, or compare with the percentage-based one rep max chart.
Frequently asked questions
What does RPE 8 mean?
RPE 8 means you finished the set with about 2 good reps left. RPE 9 means 1 rep left and RPE 10 means none left. This is the reps-in-reserve version of RPE that most lifters use.
How do I calculate my 1RM from RPE?
Add your reps in reserve to the reps you did, then use a 1RM formula. For 225 lb × 3 at RPE 8, that is 225 × 5 reps, which gives about 259.9 lb with our formula average. The calculator above does this for you.
What is RIR?
RIR means reps in reserve: the number of extra reps you could have done with good form. RIR = 10 − RPE, so RPE 8 is 2 RIR.
Is RPE accurate for beginners?
It is less accurate at first. In research, experienced lifters rated their sets more accurately than novices. Beginners can still use RPE, but should expect to get better at it over a few months.
What RPE should I train at?
Many programs use RPE 6 to 8 for most sets, which leaves 2 to 4 reps in reserve, and save RPE 9 to 10 for occasional heavy work. Your program or coach should set the targets.
Sources
- Zourdos MC, Klemp A, Dolan C, et al. Novel resistance training-specific rating of perceived exertion scale measuring repetitions in reserve. Journal of Strength and Conditioning Research. 2016;30(1):267-275. PubMed 26049792
- Helms ER, Cronin J, Storey A, Zourdos MC. Application of the repetitions in reserve-based rating of perceived exertion scale for resistance training. Strength and Conditioning Journal. 2016;38(4):42-49. PubMed 27531969
- LeSuer DA, McCormick JH, Mayhew JL, Wasserstein RL, Arnold MD. The accuracy of prediction equations for estimating 1-RM performance in the bench press, squat, and deadlift. Journal of Strength and Conditioning Research. 1997;11(4):211-213. Abstract