RPE Calculator and RPE Chart: Find Your Max and Next Weight

Enter the weight, reps, and how hard the set felt on the 1–10 RPE scale. The calculator estimates your one-rep max or gives you a target weight. RPE 10 means no reps left; RPE 9, one; RPE 8, two; and RPE 7, three.

How do you use the RPE calculator?

Use it to estimate your max from a completed set or choose a working weight for a target set. Keep estimates to 10 reps or fewer at RPE 7 or higher.

To estimate your max:

1. Enter the weight, reps, and RPE from a completed set.
2. The calculator uses the chart percentage to estimate your one-rep max (e1RM).

To pick a working weight:

1. Enter your estimated max or today’s top set, plus target reps and RPE.
2. Use the result as a guide and round to loadable plates: 5 lb (2.5 kg) increments.

Rate the set right after your last rep: how many more clean reps could you have done? Subtract that number from 10. RPE 5–6 means about four to six reps left (Helms et al., 2016). Half points such as 8.5 and 9.5 cover sets between whole numbers. See what RPE means, with the full 1–10 scale, reps in reserve (RIR), explained, and all our lifting calculators.

Where does the RPE chart come from, and how does it work?

The chart used by many RPE calculators was published by powerlifter and coach Mike Tuchscherer of Reactive Training Systems. It maps reps at a given RPE to a percentage of your max; each point below RPE 10 represents one more rep you could have done.

The lifting scale based on reps in reserve appeared in The Reactive Training Systems Manual in 2008, adapted from Borg’s earlier effort scale (Helms et al., 2016). The chart is a practical average, not a law; Tuchscherer recommends customizing it to the athlete (Reactive Training Systems).

• 1 rep at RPE 9 = 95.5%, the same as 2 reps at RPE 10.
• 3 reps at RPE 8 = 86.3%, the same as 5 reps at RPE 10.
• 5 reps at RPE 8 = 81.1%, the same as 7 reps at RPE 10.

The last example also matches the Epley formula’s 7-rep value of 81.1%; that agreement is an observation, not the calculator’s formula (Epley formula reference). The calculator divides the weight by the chart percentage to estimate max, then multiplies that max by the target percentage to prescribe a load. It shows the exact and rounded loads in 5 lb (2.5 kg) increments. The chart covers 1–12 reps and RPE 6.5–10, but estimates become less reliable above 10 reps (Fitness Volt). For sets taken to failure, use the 1RM calculator instead.

How much is RPE 8, RPE 7 and RPE 9 in percent of your max?

It depends on reps. A single at RPE 8 is about 92% of your max; five reps are about 81%, and eight reps about 74%. At the same rep count, each whole RPE point shifts the load by roughly 2.5–3.5 percentage points, and by 4.5 between a true max single and an RPE 9 single (Reactive Training Systems RPE chart).

RPE 7 means three good reps left; RPE 8, two; RPE 9, one. For 275 lb (125 kg) for 5 reps at RPE 8:

1. 5 at RPE 8 is 81.1%, estimating a max of about 339 lb (154 kg).
2. A target of 3 at RPE 9 is 89.2%, or about 302 lb; round to 300 lb.
3. Back-off sets of 5 at RPE 7 are 78.6%, or about 266 lb; round to 265 lb.

How accurate is an RPE-based max estimate?

Accuracy depends on judging reps left, and lifters commonly underestimate them. Across 12 studies and 414 participants, they underpredicted remaining reps by about one on average; accuracy improved near failure and with sets of 12 reps or fewer (Halperin et al., 2022).

• In a study of 141 participants using machines, the least experienced underpredicted by about 4–5 reps; the most experienced by 1–2 (Steele et al., 2017).
• Experienced squatters rated a true max 9.80 on average; novices rated it 8.96 (Helms et al., 2016).
• RPE is most useful at 7–10. Novices should practice recording RIR before using it to set intensity (Helms et al., 2016).

If a set logged at RPE 8 was really RPE 6, the calculator underestimates e1RM and future weights. The chart is fine; the rating is the weak link.

How do you get your RPE ratings honest?

Calibrate your judgment against real failure with a safe, low-skill exercise. Compare your predicted reps left with what you could actually do, and rate the set immediately.

1. Occasionally take a safe machine, dumbbell press, or leg press set to failure.
2. Film or note bar speed; clear slowdown usually means RPE 8 or higher.
3. Log your rating and last rep immediately; don’t revise after resting.
4. If “RPE 8” sets never slow down, they may be RPE 6–7.
5. If new to RPE, log guesses while adding weight or reps until ratings become reliable (Helms et al., 2016).

How do you use RPE to set weights and track progress?

Use one top set to estimate that day’s max, then base back-off sets on it. Tracking weekly e1RM helps account for readiness and show whether progress continues.

1. Work up to a top set at the prescribed reps and RPE.
2. Enter it to calculate today’s e1RM.
3. Set back-offs from that estimate, round to loadable plates, and log e1RM weekly.

If a set misses the target RPE, one study adjusted load about 2% per half-point: reduce it if too hard, increase it if too easy. In an 8-week study of 21 trained men, RPE trainees gained slightly more squat and bench strength than the percentage group, but differences were not statistically significant (Helms et al., 2018). For long-term progress, see rules for getting stronger after year one.

What if your RPE-based max stops going up?

A flat e1RM from honestly rated sets over three or four weeks signals a stall more clearly than one failed max attempt. Check that sets are hard, then review progression, practice, recovery, and diet.

• Inflated RPE ratings may hide sets that are too easy.
• Check whether load or reps should increase and whether you practice the lift enough.
• Consider heavy training, sleep, stress, cardio, and a calorie deficit.

Several factors may contribute. To identify which issue to address first, find out what’s actually stalling your lifts.

FAQ

How do I figure out my RPE?

Right after your last rep, ask how many more clean reps you could have done with the same form, then subtract that number from 10. One left is RPE 9, two is RPE 8, and three is RPE 7; use half points between whole numbers.

How much is 8 RPE?

RPE 8 means you stopped with about two good reps left. On the Reactive Training Systems chart, a single is about 92% of your max, a triple 86%, five reps 81%, and eight reps 74%.

What is a 7 RPE?

RPE 7 means you finished with about three reps left, with the bar still moving well and your form holding. Five reps at RPE 7 are about 79% of your max; a single is about 89%.

How can I calculate my 1 rep max from RPE?

Divide the weight by the chart percentage for your reps and RPE. Five reps at RPE 8 is 81.1%, so 275 lb for 5 estimates a max of about 339 lb; use sets of 10 reps or fewer at RPE 7 or higher.