What RPE is
RPE rates how hard a set was, from 6 to 10. After a hard set you give it one number, and Kiloton plans your next load from it.
At a glance
| RPE | RIR | What it felt like |
|---|---|---|
| 10 | 0 | Nothing left. You could not have added weight or a rep. |
| 9.5 | 0.5 | No more reps — but you could have gone slightly heavier. |
| 9 | 1 | One more rep was there. |
| 8.5 | 1.5 | One more for sure, possibly two. |
| 8 | 2 | Two more reps in the tank. |
| 7 | 3 | Three left. Comfortably fast, still work. |
| 6 | 4 | Four or more left — warm-up territory. |
RIR = 10 − RPE
Reps in reserve is the same scale read from the other end: how many reps you had left. Subtract the RPE from 10 and you have it, so RPE 8 is 2 in reserve. There is no table to memorise and no rounding.
Kiloton asks in whichever you pick when you set it up. Only the words change, and you can switch in Settings, under Units and effort.
Halves are real ratings
Between one rep left and nothing left there is a lot of room, and that is where most hard sets land. So 8.5 and 9.5 are ratings, not indecision. Half a point is roughly half a rep, and the app plans loads that finely.
How Kiloton uses it
Weight, reps and RPE together give an estimated one-rep max. On the chart Kiloton uses, 5 reps at RPE 8 is 81.1% of your max, so 140 kg for 5 at RPE 8 estimates 172.6 kg. Your next loads are planned from that estimate.
That is why a rating is worth being honest rather than brave. A set you call 9 when it was 9.5 makes next week feel heavier than it should.