RPE calculator
Enter the weight and reps from a set and how hard it felt, as RPE or as reps in reserve (RIR). The calculator estimates your one rep max, then gives you the weight to load for any number of reps at RPE 7 to 10. It is free and needs no sign-up. Want the max from a set taken to failure? Use the one rep max calculator.
Updated October 2026
Estimated one rep max: 273.8 lb.
Target weights by reps and RPE
Rounded to 5 lb so every number loads with standard plates.
| Reps | RPE 10 | RPE 9 | RPE 8 | RPE 7 |
|---|---|---|---|---|
| 1 | 275 | 260 | 255 | 245 |
| 2 | 260 | 255 | 245 | 240 |
| 3 | 255 | 245 | 240 | 230 |
| 4 | 245 | 240 | 230 | 225 |
| 5 | 240 | 230 | 225 | 220 |
| 6 | 230 | 225 | 220 | 210 |
| 8 | 220 | 210 | 205 | 200 |
| 10 | 205 | 200 | 195 | 185 |
| 12 | 195 | 185 | 180 | 175 |
How the RPE calculator works
RPE (rate of perceived exertion) scores a set from 1 to 10. On the lifting version of the scale, the number tells you how many reps you had left: RPE 10 is nothing left, RPE 9 is one left, RPE 8 is two. So a set of 5 at RPE 8 is really a set you could have taken to 7.
The calculator adds the reps in reserve to the reps you did, then puts that rep max through the Epley and Brzycki formulas and averages them:
Reps to failure = reps + (10 − RPE)
Epley: 1RM = weight × (1 + reps to failure ÷ 30)
Brzycki: 1RM = weight × 36 ÷ (37 − reps to failure)
A worked example. You squat 225 lb for 5 reps at RPE 8. That is a 7-rep max. Epley gives 225 × (1 + 7 ÷ 30) = 277.5 lb, Brzycki gives 225 × 36 ÷ 30 = 270 lb, and the average is 273.8 lb. For a triple at RPE 9 next week (a 4-rep max), the table runs the formulas backwards and gives about 245 lb.
The RPE scale, and RIR next to it
| RPE | Reps in reserve | What it feels like |
|---|---|---|
| 10 | 0 | Maximal. No further rep was possible. |
| 9.5 | 0 to 1 | Maybe one more, or more weight would have failed. |
| 9 | 1 | One more rep was definitely there. |
| 8.5 | 1 to 2 | One more for sure, maybe two. |
| 8 | 2 | Two more reps were there. |
| 7 | 3 | Fast and solid, three more in reserve. |
| 6 | 4 or more | Warm-up or speed-work effort. |
RIR is the same idea counted the other way: RPE = 10 − RIR. The full chart, and how to get better at judging it, is in the reps in reserve guide.
How to use the target-weight table
Programs written in RPE give you sets like “3 × 5 @ RPE 8”. Find the row for 5 reps and the RPE 8 column: that is the weight to start with. If the first set feels easier or harder than the RPE you were aiming for, adjust the next set by a plate step rather than sticking to the number.
The same table drives progressive overload: if last week’s 5 at RPE 8 felt like RPE 7 this week, enter the new set and the estimate, and every target weight, moves up with you.
When not to trust the number
- Reps plus reps in reserve is above 12. Past that, endurance matters more than strength and the formulas drift apart.
- You are new to RPE. Most lifters call RPE 8 when they had three or four reps left, which makes the estimate too low.
- The lift is a machine, cable or small isolation movement. The formulas are built around barbell lifts.
Let SayLift keep the numbers
SayLift is an iPhone workout tracker you log by talking. Say “squat, 225 for 5, felt like an 8” and the set is written down with the effort as a note. Its coach reads your logged history and gives each exercise one instruction, increase, hold, decrease, deload, restart, calibrate, with the working weight for next session. The coach works from the weights and reps you log, not from your RPE notes.
SayLift is iPhone only, 3 days free then $4.17 a month, billed $49.99 a year. This calculator stays free either way.
Start the free trialFrequently asked questions
What is an RPE calculator?
It turns a set you did, the weight, the reps and how hard it felt on the RPE scale, into an estimated one rep max. From that estimate it works out the weight to use for any other number of reps at any RPE.
What does RPE 8 mean?
RPE 8 means you finished the set with about two good reps left. RPE 10 is a set where no further rep was possible, RPE 9 leaves one rep, and RPE 7 leaves three.
How is RPE different from RIR?
They describe the same thing from opposite ends. RIR (reps in reserve) counts the reps you had left; RPE scores the effort out of 10. On the lifting scale RPE is 10 minus RIR, so 2 RIR is RPE 8. The calculator accepts either.
How accurate is an RPE-based 1RM estimate?
Good enough to plan with, if your RPE calls are honest and the set was 12 reps or fewer including the reps you had left. Most lifters underestimate how many reps they have left at first, which makes the estimate come out low. It gets better with practice.
What RPE should I train at?
Most working sets in common programs sit between RPE 7 and 9, leaving one to three reps in reserve. RPE 10 is usually saved for tests or the last set of an exercise, because sets to failure cost more recovery for little extra benefit.
Which formula does this RPE calculator use?
It treats a set at RPE r as 10 − r reps short of failure, so 5 reps at RPE 8 counts as a 7-rep max. That rep max goes into the Epley and Brzycki formulas, and the calculator shows the average of the two, the same method as the one rep max calculator on this site.
Related
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