RPE / RIR Calculator
Convert between Rate of Perceived Exertion (RPE), Reps in Reserve (RIR), and percentage of 1RM. Master autoregulated training.
RPE / RIR Converter
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RPE to RIR Conversion Table
| RPE | RIR | % of 1RM | Description |
|---|---|---|---|
| @10 | 0 | 100% | Maximum effort, no reps left |
| @9.5 | 0.5 | 98% | Could maybe do 0.5 more rep |
| @9 | 1 | 96% | 1 rep in reserve |
| @8.5 | 1.5 | 94% | 1-2 reps in reserve |
| @8 | 2 | 92% | 2 reps in reserve |
| @7.5 | 2.5 | 89% | 2-3 reps in reserve |
| @7 | 3 | 86% | 3 reps in reserve |
| @6.5 | 3.5 | 83% | 3-4 reps in reserve |
| @6 | 4 | 80% | 4 reps in reserve |
| @5 | 5 | 75% | Light effort, 5+ reps left |
Training Zones by RPE
Strength/Power
RPE
9-10
% of 1RM
90-100%
Reps
1-5
Heavy singles, doubles, triples. Maximum strength development.
Strength-Hypertrophy
RPE
8-9
% of 1RM
85-92%
Reps
5-8
Heavy compound work. Builds strength and size.
Hypertrophy
RPE
7-8
% of 1RM
70-85%
Reps
8-12
Primary muscle building zone. Moderate load, moderate reps.
Endurance/Volume
RPE
5-7
% of 1RM
60-75%
Reps
12-20+
High rep work for endurance and metabolic stress.
Understanding RPE & RIR
RPE (Rate of Perceived Exertion) is a 1-10 scale measuring how hard a set feels. An RPE of 10 means you couldn't do another rep, while RPE 7 means you had about 3 reps left in the tank.
RIR (Reps in Reserve) is simply how many more reps you could have done. RIR = 10 - RPE. So RPE 8 = 2 RIR (2 reps left).
Why use RPE? RPE accounts for daily fluctuations in strength. Instead of lifting a fixed weight, you adjust based on how you feel that day. This leads to better autoregulation and long-term progress.
Note: RPE takes practice to learn. Most beginners underestimate their RPE (think they're at 10 when they're really at 7-8). Video yourself and review to calibrate your perception.
Related Tools
Want AI to track your RPE automatically?
Arvo monitors your RIR every set and adjusts weights in real-time based on your performance.
- Set-by-set AI adaptation
- Automatic fatigue detection
- Real-time weight suggestions
Want to Learn More?
Dive deeper into autoregulated training with our comprehensive guides.
What is RPE?
Rate of Perceived Exertion (RPE) is a subjective scale from 1-10 that measures how hard a set feels relative to your maximum effort. It was popularized for strength training by Dr. Mike Zourdos and is now used by top powerlifters and bodybuilders worldwide.
Unlike fixed percentages, RPE accounts for daily fluctuations in strength due to sleep, stress, nutrition, and recovery. This makes it a more responsive tool for autoregulating your training.
The RPE Scale Explained
Maximum effort
You couldn't do another rep. True failure.
Almost max
Maybe could squeeze out a half rep with perfect form.
Very hard
Could definitely do 1 more rep, but it would be a grinder.
Hard
2 reps left in the tank. Challenging but controlled.
Moderate-hard
3 reps left. Speed starts to slow noticeably.
Moderate
4 reps left. Weight moves well but requires focus.
Easy
Warm-up territory. Could do many more reps.
How to Use RPE in Your Training
Start with a target RPE
Your program might say 'Squat 3x5 @RPE 8'. This means 3 sets of 5 reps, each set should feel like you have 2 reps left.
Warm up and assess
Do your warm-up sets, feeling how the weight moves. Estimate what weight will hit your target RPE.
Adjust in real-time
If your first work set feels easier than expected (RPE 7), add weight. If it's harder (RPE 9), reduce.
Record and learn
Write down actual RPE for each set. Over time, you'll calibrate your perception and predict loads better.
Benefits of RPE Training
Daily Autoregulation
Train harder on good days, back off on bad days. No more forcing weights when you're fatigued.
Injury Prevention
RPE catches when you're overreaching. High RPE with lower weights signals accumulated fatigue.
Better Progress
By matching intensity to your daily capacity, you accumulate more quality volume over time.
Mind-Muscle Connection
Rating RPE forces you to pay attention to how each set actually feels.
Factors That Affect Your RPE Accuracy
Many factors influence how hard a set feels. Understanding these helps you interpret RPE more accurately.
Sleep quality
Poor sleep makes everything feel harder, adding +1-2 RPE to perceived effort
Nutrition
Training fasted or underfed increases perceived effort significantly
Caffeine
Can mask fatigue and lower perceived RPE — be aware of this effect
Time of day
Most people are strongest 4-6 hours after waking
Stress levels
Life stress competes with recovery and raises perceived effort
Exercise familiarity
New exercises feel harder due to technique demands
Rep speed
Faster reps feel easier even at the same load
Music/environment
Optimal environment can lower RPE by 0.5-1 points
Common RPE Mistakes and How to Calibrate
Most lifters make predictable errors when rating RPE. Learn to spot and correct them.
❌ Ego-driven low RPE
✅ Video yourself — if bar speed slows significantly, add 1-2 points to your estimate
❌ Fear-driven high RPE
✅ Occasionally test true maxes to recalibrate what RPE 10 actually feels like
❌ Inconsistent standards
✅ Define YOUR RPE 10 clearly and work backwards consistently
❌ Ignoring exercise differences
✅ Isolation exercises often feel higher RPE at the same relative intensity
💡 Keep an RPE log — compare estimated vs actual over time to improve accuracy.
How RPE Feels Different by Exercise Type
RPE perception varies significantly between exercise types.
| Exercise Type | How It Feels |
|---|---|
| Compound Barbell (Squat, Bench, Deadlift) | Clear 'reps in reserve' sense. Bar speed is a reliable indicator of effort. |
| Compound Dumbbell | Stability limits often fail before muscles. Feels like higher RPE at same relative intensity. |
| Machine Exercises | More accurate RPE — no stability variable. Easier to push close to true failure. |
| Isolation Exercises | Burn and local fatigue dominate — harder to judge true RIR accurately. |
| Bodyweight Exercises | Highly dependent on bodyweight — recalibrate as weight changes. |
Using RPE Across Training Phases
Different training phases call for different RPE targets.
| Phase | RPE | Reason |
|---|---|---|
| Hypertrophy Block | RPE 7-8 | Volume is the main driver — save intensity for strength blocks |
| Strength Block | RPE 8-9 | Higher intensity needed for neural adaptations and strength gains |
| Peaking | RPE 9-10 | Testing your limits and expressing strength before competition |
| Deload | RPE 5-6 | Allow accumulated fatigue to dissipate while maintaining movement patterns |
Optimal RPE Targets by Training Goal
Match your target RPE to your specific training goal.
| Goal | RPE | Typical Sets | Note |
|---|---|---|---|
| Maximum Strength | 8-10 | Singles to triples | High intensity needed for neural adaptations |
| Hypertrophy | 7-9 | 6-12 rep sets | Close to failure without excessive fatigue accumulation |
| Muscular Endurance | 6-8 | 15-20+ reps | Metabolic stress is the driver, not max effort |
| Technique Work | 5-7 | Any rep range | Low fatigue allows focus on perfecting form |
Common RPE Training Myths Debunked
❌ You must always train to failure
✅ RPE 7-8 is sufficient for muscle growth with less accumulated fatigue. Leaving 2-3 reps in reserve optimizes the stimulus-to-fatigue ratio.
❌ RPE is subjective and unreliable
✅ With practice, RPE becomes accurate and improves autoregulation. Studies show trained lifters can estimate RIR within 1 rep accuracy.
❌ Percentages are more precise than RPE
✅ Percentages don't account for daily variability. Your 80% today may feel like 85% or 75% depending on recovery, sleep, and stress.
❌ RPE 10 every set equals maximum gains
✅ Constant failure training increases fatigue and injury risk disproportionately. Most sets should be RPE 7-9 for sustainable progress.
❌ Beginners can't use RPE
✅ Beginners can start using RPE immediately, calibrating over time. It develops body awareness and prevents early overtraining.
Frequently Asked Questions
What is RPE in weightlifting?
RPE (Rate of Perceived Exertion) is a 1-10 scale measuring how hard a set feels. RPE 10 means maximum effort with no reps left, RPE 8 means you could have done 2 more reps, and so on. It's used to autoregulate training intensity.
What is RIR (Reps in Reserve)?
RIR stands for Reps in Reserve - how many more reps you could have done before failure. RIR is essentially 10 minus RPE. So RPE 8 = 2 RIR (2 reps left in the tank).
How do I convert RPE to percentage of 1RM?
RPE roughly correlates to %1RM: RPE 10 ≈ 100%, RPE 9 ≈ 96%, RPE 8 ≈ 92%, RPE 7 ≈ 86%. However, this varies by individual and rep range. Our chart provides standard conversions.
Why use RPE instead of percentages?
RPE accounts for daily fluctuations in strength (sleep, stress, nutrition). Instead of blindly following percentages, you adjust based on how you actually feel. This leads to better long-term progress and injury prevention.
How do I learn to rate RPE accurately?
It takes practice. Start by recording your sets and reviewing them. Ask: 'How many more reps could I have done?' Most beginners underestimate their RPE (think they're at 10 when they're at 7-8). Video yourself to calibrate.
What RPE should I train at?
It depends on your goal. For strength: RPE 8-9 for main lifts. For hypertrophy: RPE 7-8 for most sets. Leave 2-3 reps in reserve most of the time. Only go to failure (RPE 10) occasionally.
Automatic RPE Tracking
This calculator shows you the conversions. Arvo tracks your RPE for every set, learns your strength curves, and automatically suggests weights based on your performance patterns.
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