Free lifting calculator
RPE Calculator
Plan your next set with rep-by-rep precision. Enter a recent lift or your 1RM and get the right load for any rep × RPE target — plus the full RPE chart, a backoff planner, and a warm-up ladder.
Advanced
Step 1 — Your reference
Per-bar, not per side.
Step 2 — What you want to lift
Target load
240 lb
For 3 reps at RPE 8 — that's about 2 reps left.
Based on 225 lb × 5 @ RPE 8. Squarely in the validated 1–6 rep, RPE 7–9.5 zone.
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Stronger · Strength Score
See where this lift puts you against global strength standards.
Your e1RM, your bodyweight, your strength level — visualised the way the Stronger app does it.
Estimates use Mike Tuchscherer's RTS-style RPE chart. RPE-based planning is a training anchor — not medical advice or a guaranteed max prediction. Adjust for the lift, the day, and how you actually feel.
RPE chart at a glance
RPE is a reps-in-reserve scale. Rate the last rep, not your mood. Here's the quick read every lifter should memorise.
| RPE | Reps in reserve | What it feels like |
|---|---|---|
| RPE 10 | 0 | Maximal. No clean rep left in the tank. |
| RPE 9.5 | 0–1 | Maybe one more, but not certain. |
| RPE 9 | 1 | One rep left. Could grind it out. |
| RPE 8.5 | 1–2 | Definitely one more, possibly two. |
| RPE 8 | 2 | Two reps left. Classic working-set zone. |
| RPE 7.5 | 2–3 | Two or three reps left. Speed crisp. |
| RPE 7 | 3 | Three reps left. Warm and ready. |
| RPE 6 and below | 4+ | Submaximal — warm-up or technique work. |
For the full table mapping every rep × RPE combination to a percent of 1RM, use the calculator's chart mode above.
What is RPE?
RPE — Rate of Perceived Exertion — was brought into modern strength training by coach Mike Tuchscherer and his Reactive Training Systems framework. In a lifting context, RPE is a reps-in-reserve scale: you rate the last rep of a set by how many more reps you could have done with good form.
- RPE 10 — maximal. No reps left. You couldn't have done another one.
- RPE 9 — 1 rep left in the tank.
- RPE 8 — 2 reps left. The classic top-set zone.
- RPE 7 — 3 reps left. Crisp, not grindy.
- RPE 6 and below — submaximal warm-up or technique work territory.
The point of RPE is that you don't have to predict the future. Instead of prescribing "225 lb for 5 reps" and discovering on the day that 225 was an absolute grinder (or comically easy), you prescribe "5 reps at RPE 8" and pick the load that actually delivers that effort right now. It auto-regulates for sleep, stress, training fatigue, and how warm-ups feel.
How to use RPE in real programs
RPE shines anywhere training is auto-regulated. A few of the most common applications:
Strength (powerlifting, conjugate, RTS)
Top set typically lands at RPE 8.5–9.5 on 1–3 reps, then backoff sets at −10 to −20% for 2–4 rounds. Plan the top set here, then expand the Plan backoff sets module for an automatic 3-round drop.
Hypertrophy / bodybuilding splits
Working sets sit at RPE 7–9 across 5–12 reps. Lower-rep work feels heavier; higher rep ranges accumulate more fatigue at the same RPE. Use the chart to keep loads honest as you fatigue across multiple sets and exercises.
Templated programs (5/3/1, PPL, GZCLP)
Most templates prescribe percentages or a top-set rep target. RPE complements them: convert the day's top set into an RPE and let backoffs auto-adjust. Useful when a percentage-based day collides with a bad night's sleep.
Single-day decisions
Walked into the gym feeling great? Choose your top set, hit RPE 8.5 instead of 8, and the backoff planner adjusts the rest of the session. Off day? Cap top sets at RPE 7.5 and the chart will hand you a lighter, still-productive load.
Common RPE mistakes
- Treating RPE 10 as the goal. True RPE 10 means a missed rep was next. Most lifters mis-rate it — they call RPE 9 sets "10s" because the bar slowed down. Real RPE 10 is rare and shouldn't be programmed routinely.
- Rating your mood, not the last rep. RPE is about that specific set, not how the warm-ups felt or whether you had coffee. Anchor on the last rep's bar speed.
- Using RPE outside its accurate range. Above 10 reps, endurance dominates strength and the chart gets noisy. Below RPE 6 you're in warm-up territory. Stay in the validated zone for serious planning.
- Skipping the log. RPE only auto-regulates if you can compare today's set against last week's. Logging is the expensive part — that's the bit the Stronger app handles automatically.
Methodology
Estimated 1RM and target loads use the canonical RTS / Tuchscherer chart for reps 1–12 at RPE 6–10 in 0.5-step increments. Cross-validated against the publicly-published versions at reactivetrainingsystems.com, rpetraining.com, liftlog.app, and gravitus.com.
Estimate 1RM: e1RM = lifted weight ÷ percent-of-1RM for that rep × RPE pair. Plan a set: target load = e1RM × percent for the target rep × RPE pair, rounded to your bar-jump increment.
We deliberately avoid Epley, Brzycki, Lombardi, O'Conner, Wathan, and other rep-count-only 1RM estimators for RPE-based planning. Those formulas can't see how the set actually felt — they treat 5 reps at RPE 7 the same as 5 reps at RPE 10. The RTS chart accounts for both axes.
The confidence indicator grades each calculation by how close the inputs are to the chart's most-validated zone (1–6 reps × RPE 7–9.5). Edge cells still compute, they just signal lower trust.
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Frequently asked questions
What is RPE in lifting?
RPE stands for Rate of Perceived Exertion. In strength training it's a reps-in-reserve scale: RPE 10 means no clean reps left, RPE 9 means about 1 rep left, RPE 8 means about 2 reps left, and so on. It lets you target a specific level of effort regardless of how recovered you are on a given day.
What’s the difference between RPE and RIR?
RPE and RIR are two sides of the same coin. RIR is reps in reserve — how many more reps you had left at the end of the set. RPE is the perceived effort of the set. RPE 10 = 0 RIR, RPE 9 = 1 RIR, RPE 8 = 2 RIR. Pick whichever language feels more natural — the chart math is identical either way.
How accurate is the RPE chart?
Most accurate in the 1–6 rep, RPE 7–9.5 zone — where the validation data is densest. Treat it as a directional planning anchor, not a guaranteed max predictor. Loads at the edges (12+ reps, RPE 6, true RPE 10) should be approximate. Always trust how the bar feels on the day over what the chart says.
Which formula does the calculator use?
We use Mike Tuchscherer's RTS-style RPE chart — the same 1–12 reps × RPE 6–10 lookup that powers most strength-focused RPE calculators. Cross-checked against reactivetrainingsystems.com, rpetraining.com, liftlog.app and gravitus.com. We don't use Epley or other 1RM-only formulas for RPE-based work because they ignore how the set actually felt.
What RPE should I train at for hypertrophy?
Most evidence-based hypertrophy programs target RPE 7–9 on working sets, 5–12 reps. You don't need RPE 10 every set to grow — and it accumulates fatigue that hurts your next session. Use the chart to keep loads honest as you fatigue across the week.
What RPE should I use for strength training?
Strength work usually sits at RPE 7.5–9 on 1–5 reps. Powerlifting and conjugate-style programs often peak top sets at RPE 9 or 9.5, then drop 10–20% for backoff sets. The "Plan a set" mode + the backoff planner is designed for exactly this workflow.
What does the Stronger app add over this calculator?
This web calculator plans one set at a time. The Stronger app logs every set with RPE, tracks your estimated 1RM and Strength Score across all your lifts, surfaces weak muscle groups, runs adaptive routines, and lets you compete with friends. Logging RPE consistently is what actually moves the needle — the app handles that part.
Why does the calculator use half-step RPE (e.g. 8.5)?
Half steps capture the real range of perceived effort. RPE 8 and RPE 9 are meaningfully different — a 0.5 step lets you distinguish a clean top set from a near-grinder without committing to a whole number. The RTS chart was designed around 0.5 steps from RPE 6.5 up.
Track every set in Stronger
The calculator plans one set. Stronger logs them all, tracks your e1RM and Strength Score across every lift, and shows whether you're actually getting stronger.