The load for a set at a given RIR, or your 1RM from a set you just did.
Load for 5 reps at RIR 2
112.5kg
113.5 kg before rounding · 81% of 1RM
Example: 140 kg 1RM, 5 reps at RIR 2. Change any field to use your own numbers.
RPE chart: % of 1RM
Each cell is the share of your 1RM a set of that many reps takes, with that many reps left. Read across for effort, down for reps.
% of 1RM by reps and reps in reserve (Epley)
Reps
RIR 0 RPE 10
RIR 1 RPE 9
RIR 2 RPE 8
RIR 3 RPE 7
1
100.0
93.8
90.9
88.2
2
93.8
90.9
88.2
85.7
3
90.9
88.2
85.7
83.3
4
88.2
85.7
83.3
81.1
5
85.7
83.3
81.1
78.9
6
83.3
81.1
78.9
76.9
7
81.1
78.9
76.9
75.0
8
78.9
76.9
75.0
73.2
9
76.9
75.0
73.2
71.4
10
75.0
73.2
71.4
69.8
11
73.2
71.4
69.8
68.2
12
71.4
69.8
68.2
66.7
Epley against the RTS chart
The other chart in wide use, at RPE 10. The two sit within 1.3 points of each other from 1 to 10 reps.
% of 1RM at RPE 10
Reps
Epley
RTS
Difference
1
100.0
100
0.0
2
93.8
95
−1.3
3
90.9
92
−1.1
4
88.2
89
−0.8
5
85.7
86
−0.3
6
83.3
84
−0.7
7
81.1
81
+0.1
8
78.9
79
−0.1
9
76.9
76
+0.9
10
75.0
74
+1.0
How it works
RIR is the reps you had left when you stopped. RPE is 10 minus RIR, so RPE 8 means two reps left and RPE 10 means none (Zourdos 2016). RPE 8.5 is one or two left.
Reps plus RIR gives the reps you could have done. That goes through Epley:
% of 1RM = 100 / (1 + (reps + RIR) / 30)
a single with nothing left is 100%
For a load, we multiply your 1RM by that share. It rounds to the nearest 1.25 kg up to 40 kg, 2.5 kg above, or 5 lb. For your 1RM, the formula runs the other way: weight × (1 + (reps + RIR) / 30). Here RIR above 3 counts as 3, since lifters judge it poorly far from failure.
How far to trust it
The chart is one formula. Real lifters spread around it. Pooled across studies, lifters at 80% of 1RM managed about 10 reps, give or take 2.5 from one person to the next, where Epley says 7.5. Leg exercises ran to more reps at the same load than presses (Nuzzo 2024).
Lifters misjudge RIR by about a rep, usually thinking they have fewer left than they do. They judge it better near failure and in sets of 12 or fewer (Halperin 2022).
So the 1RM comes with a likely range: reps to failure plus or minus a quarter, and one more rep when you enter RIR. Five to failure gives a narrow range. Twelve at RIR 3 gives a wide one. When the number matters, test with 1 to 6 reps near failure.
The RTS chart gives slightly different numbers. Helms and colleagues, who published an RIR-based %1RM chart, wrote that it should not be viewed as "an absolute conversion tool" (Helms 2016). The same goes for this chart.
How RPE and RIR relate, and how well lifters judge reps left, with the studies: RPE vs RIR.
Sources
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. doi.org/10.1519/JSC.0000000000001049
Helms ER, Cronin JB, 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. doi.org/10.1519/SSC.0000000000000218
Halperin I, Malleron T, Har-Nir I, et al. Accuracy in predicting repetitions to task failure in resistance exercise: a scoping review and exploratory meta-analysis. Sports Med. 2022;52:377–390. doi.org/10.1007/s40279-021-01559-x
Nuzzo JL, Pinto MD, Nosaka K, Steele J. Maximal number of repetitions at percentages of the one repetition maximum: a meta-regression and moderator analysis of sex, age, training status, and exercise. Sports Med. 2024;54(2):303–321. doi.org/10.1007/s40279-023-01937-7
Epley B. Poundage chart. Boyd Epley Workout. Lincoln, NE; 1985.
