One Rep Max Calculator (Multi-Formula)
Compare six common 1RM formulas side by side: Epley, Brzycki, Lombardi, Mayhew, O'Conner, and Wathen. Use the spread and average as a practical estimate range.
RPE to Percentage Converter Calculator
Convert RPE (Rate of Perceived Exertion) to percentage of 1RM and vice versa. Full RPE-Reps chart based on Mike Tuchscherer's RIR-based RPE scale.
lb
5 reps @ RPE 8
258.3 lb
82% of 1RM | 2 RIR
Working Weight⧉
258.3 lb
% of 1RM⧉
82%
Reps in Reserve⧉
2
1RM⧉
315 lb
Reverse Lookup: Find Your RPE
Estimated RPE
RPE 7
~79.4% of 1RM
Complete RPE-Reps Chart (% of 1RM)
| RPE | 1r | 2r | 3r | 4r | 5r | 6r | 7r | 8r | 9r | 10r | 11r | 12r |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 10 | 100% | 97% | 94% | 92% | 89% | 86% | 84% | 81% | 79% | 76% | 74% | 71% |
| 9.5 | 98% | 95% | 93% | 90% | 88% | 85% | 82% | 80% | 77% | 75% | 72% | 69% |
| 9 | 96% | 93% | 91% | 88% | 86% | 83% | 81% | 78% | 76% | 73% | 71% | 68% |
| 8.5 | 94% | 91% | 89% | 87% | 84% | 82% | 79% | 77% | 74% | 72% | 69% | 67% |
| 8 | 92% | 89% | 87% | 85% | 82% | 80% | 77% | 75% | 72% | 70% | 68% | 65% |
| 7.5 | 91% | 88% | 86% | 83% | 81% | 78% | 76% | 73% | 71% | 68% | 66% | 64% |
| 7 | 89% | 86% | 84% | 82% | 79% | 77% | 74% | 72% | 69% | 67% | 65% | 62% |
| 6.5 | 88% | 85% | 82% | 80% | 78% | 75% | 73% | 70% | 68% | 65% | 63% | 61% |
| 6 | 86% | 83% | 81% | 78% | 76% | 73% | 71% | 69% | 66% | 64% | 62% | 59% |
Based on Mike Tuchscherer's Reactive Training Systems data. Individual variation of ±2-3% is normal.
Weight at Each RPE for 5 Reps
RPE 10
89%280.4 lb
RPE 9.5
88%277.2 lb
RPE 9
86%270.9 lb
RPE 8.5
84%264.6 lb
RPE 8
82%258.3 lb
RPE 7.5
81%255.2 lb
RPE 7
79%248.9 lb
RPE 6.5
78%245.7 lb
RPE 6
76%239.4 lb
Planning notes, formulas, and examples
About the RPE to Percentage Converter Calculator
RPE-based loading links perceived effort to an approximate percentage of 1RM, which helps lifters adjust working weights when daily readiness changes.
This calculator converts between RPE, reps, and estimated percentage, and also provides a lookup table for common combinations used in programming.
Use it when you want to translate an RPE target into bar weight or estimate what a completed set represented.
When This Page Helps
It is useful for turning RPE prescriptions into actual loads without guessing percentages each session. The chart is still a starting framework and works best when calibrated to your own lifting history.
How to Use the Inputs
- Enter your estimated or tested 1RM for the exercise.
- Select the target RPE (6-10) from the dropdown.
- Select the number of reps you plan to do.
- View the recommended working weight.
- Reference the full RPE-Reps chart for all combinations.
- Use "reverse lookup" to find your RPE from a weight and reps.
Formula used
Approximate percentage mapping (RPE → % 1RM at given reps):
At 1 rep: RPE 10 = 100%, RPE 9.5 = 98%, RPE 9 = 96%, RPE 8.5 = 94%, RPE 8 = 92%, RPE 7.5 = 91%, RPE 7 = 89%, RPE 6.5 = 88%, RPE 6 = 86%
Each additional rep reduces the percentage by ~3%.
Working Weight = 1RM × (percentage / 100)Example Calculation
Result: 258.3 lbs (82% of 1RM)
For 5 reps at RPE 8 (about 2 reps in reserve), this chart maps to 82% of 1RM. So 315 × 0.82 = 258.3 lbs. Treat that as a starting load and adjust if your actual reps-in-reserve differ.
Tips & Best Practices
- RPE accuracy improves with experience — beginners often underestimate how many reps they have left.
- RPE 6-7 is ideal for warm-up and technique work; RPE 8-9 for main sets; RPE 9.5-10 for testing.
- Most training should live between RPE 7 and 9 — avoid grinding RPE 10 sets in regular training.
- Half-RPE values (7.5, 8.5, 9.5) add precision and are commonly used in modern programming.
- If your RPE consistently feels higher than the chart predicts, you may need to retest your 1RM.
- Record both weight AND RPE for every set to calibrate your personal RPE-percentage relationship.
The History of RPE in Strength Training
The original RPE scale was developed by Gunnar Borg in the 1960s for cardiovascular exercise (6-20 scale). Mike Tuchscherer adapted it for strength training in the 2000s, creating the RIR-based 1-10 scale now commonly used in strength training. Reactive Training Systems (RTS) helped popularize RPE-based autoregulation.
RPE vs Percentage-Based Training
Percentage-based programs prescribe fixed loads based on a tested 1RM. They're simple and easy to plan in advance. RPE adds a way to adjust those loads when daily readiness is higher or lower than expected. Both approaches can work well, and many programs combine percentages with RPE caps or back-off guidance.
Building Your Personal RPE Chart
The standard chart is an average. Experienced lifters often build personal charts by logging RPE and actual loads over time, then fitting their own percentages. Over time, you may learn that your personal RPE 8 at 3 reps is 88%, even if the standard chart says 89%. That makes the chart more individualized without turning it into an exact science.
Sources & Methodology
Last updated:
Methodology
This worksheet turns a training rule into weekly set, rep, or rest planning guidance. It is meant for programming context rather than as an official protocol or medical rule.
Sources
- ACSM Position Stand: Progression Models in Resistance Training for Healthy Adults (American College of Sports Medicine) — Foundational progression and loading guidance.
- Essentials of Strength Training and Conditioning (NSCA) — General programming context and set/rep structures.
- 5/3/1: The Simplest and Most Effective Training System for Raw Strength (Jim Wendler) — Used for the 5/3/1 planning worksheet.
Frequently Asked Questions
RPE (Rate of Perceived Exertion) is a 1-10 scale measuring how hard a set felt. In strength training, the RIR-based version is used: RPE 10 = no reps left (maximal), RPE 9 = 1 rep left, RPE 8 = 2 reps left, RPE 7 = 3 reps left, and so on. It was adapted for strength training by Mike Tuchscherer.
RIR stands for Reps In Reserve — the number of additional reps you could have performed before failure. RPE 10 = 0 RIR, RPE 9 = 1 RIR, RPE 8 = 2 RIR, etc. RIR and RPE are inversely related: RPE = 10 − RIR.
The chart provides approximate averages based on data from experienced lifters. Individual variation of ±2-3% is normal. Factors like exercise type, fatigue, and training age affect the relationship. Use the chart as a starting point and calibrate to your personal data over time.
Beginners can learn RPE, but it takes practice to calibrate accurately. New lifters often leave 3-4 reps in reserve when they think they're at RPE 9. Starting with percentage-based programs and gradually incorporating RPE is often a simpler approach for beginners.
Most productive training occurs at RPE 7-9. For strength: RPE 8-9 at 1-5 reps. For hypertrophy: RPE 7-9 at 6-12 reps. Technique work: RPE 6-7. Testing/peaking: RPE 9.5-10. Avoid chronic RPE 10 training — it accumulates excessive fatigue.
One of RPE's main uses is handling day-to-day variation. On a good day, RPE 8 at 5 reps might be 255 lbs. On a lower-readiness day, it might be 240 lbs. The target effort stays the same while the load moves with recovery and fatigue.
RPE works best for compound movements where effort is clearly felt. For isolation exercises, RPE is less reliable because local fatigue clouds perception. Many coaches use RPE for compounds and a simple "close to failure" approach for accessories.
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