📊Free strength calculator

RPE Calculator

Enter a set — weight, reps, and RPE — and the RPE calculator estimates your one-rep max, then projects the load for any target reps at RPE 7 through 10. Because RPE captures reps in reserve, a hard-but-not-maximal set still gives an accurate 1RM estimate.

RPE of the set

Estimated one-rep max

270 lb

RPE 8 = 2 reps in reserve → treated as 7 effective reps to failure.

Prefer straight sets to failure? Use the 1RM calculator, then program from the lifting percentage chart. More free tools →

Projected loads by reps and RPE

Reps@ RPE 10 (lb)@ RPE 9 (lb)@ RPE 8 (lb)@ RPE 7 (lb)
1270262.5255247.5
2262.5255247.5240
3255247.5240232.5
4247.5240232.5225
5240232.5225217.5
6232.5225217.5210
7225217.5210202.5
8217.5210202.5197.5
9210202.5197.5193
10202.5197.5193188.5

Loads are derived from the same estimator the NutriMind app uses (Brzycki at ≤10 effective reps, Epley above), inverted for each target reps + RPE combination. Published RPE charts are built from slightly different formulas or lifter data, so expect numbers elsewhere to differ by 1–3%.

RPE to RIR conversion

RPEReps in reserveWhat it feels like
100Max effort — no more reps possible
9.50–1Maybe one more rep, maybe not
91One rep left in the tank
8.51–2Definitely one more, possibly two
82Two reps left — classic hard working set
7.52–3Two, probably three reps left
73Three reps left — solid volume work
64Four reps left — speed or technique work

RPE tells you how hard. NutriMind tells you what's next.

NutriMind estimates your 1RM from every logged set and auto-progresses your loads week to week — and its AI nutrition coaching keeps calories and protein matched to your training, which is where most strength plateaus actually come from.

Frequently asked questions

What is RPE in lifting?

RPE (Rating of Perceived Exertion) is a 1–10 scale for how hard a set was, anchored to proximity to failure: RPE 10 means you had nothing left, RPE 9 means one more rep was possible, RPE 8 means two, and so on. It lets programs prescribe effort ("3 × 5 @ RPE 8") instead of fixed weights, so the load auto-adjusts to how strong you are TODAY.

What's the difference between RPE and RIR?

They're two views of the same thing. RIR (Reps In Reserve) counts the reps you had left; RPE rates the effort. For sets near failure they mirror each other: RPE 10 = 0 RIR, RPE 9 = 1 RIR, RPE 8 = 2 RIR. This calculator converts your RPE to RIR, adds it to your reps to get "effective reps to failure," and feeds that into the 1RM estimator.

Why do RPE charts from different sources disagree?

Every chart is built on a model — a rep-max formula or averaged lifter data — and the models diverge, especially at higher reps. This page uses the exact estimator the NutriMind app trains you with (Brzycki at 10 or fewer effective reps, Epley above), so numbers here match your in-app targets; other charts will typically sit within 1–3% of these values.

How accurate is RPE-based 1RM estimation?

For experienced lifters rating honestly, very good — usually within a few percent on sets of 2–8 reps at RPE 7+. Accuracy drops when RPE is guessed poorly (beginners commonly underrate; most people have more reps left than they think) and on very high-rep sets, where endurance blurs the rep-to-max relationship. Calibrate occasionally by taking a set all the way to failure.

What RPE should my working sets be?

Most productive training lives at RPE 6–9. A common structure: strength work at RPE 7–8.5 for 1–6 reps, hypertrophy work at RPE 7–9 for 6–15 reps, and only occasional RPE 10 sets — going to true failure every set adds fatigue faster than it adds stimulus.