1RM Calculator
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Recommended training zones
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The 1RM (One Rep Max) represents the maximum weight you can lift for a single repetition on a given exercise. It's a fundamental metric in bodybuilding that allows you to intelligently program your workouts and measure your progression in pure strength.
Our calculator uses the Epley formula, recognized for its accuracy, to estimate your 1RM without needing to test your actual maximum (which can be risky and exhausting).
What is 1RM?
Absolute strength measure
The 1RM indicates your maximum strength on a specific movement. It's the universal standard for comparing strength levels between athletes.
Programming tool
Knowing your 1RM allows you to precisely calculate your working loads according to your goal (strength, hypertrophy, endurance).
Progress tracking
Testing your 1RM regularly (every 2-3 months) allows you to objectively measure your strength gains and adjust your program.
Safety and efficiency
Using a calculator avoids actually testing your 1RM, which is taxing on the nervous system and presents injury risks.
Important note: The estimated 1RM is an approximation. For more precision, test your maximum with repetitions between 3 and 8. Beyond 10 reps, the estimation becomes less reliable as muscular endurance becomes a limiting factor.
Track your 1RMs with BenchRepHow to use your 1RM
1 Calculate your training loads
Once your 1RM is known, you can program your sessions using percentages adapted to your goal.
2 Program your training cycles
Use your 1RM to create periodization cycles that optimize your strength and mass gains.
Weeks 1-4
- • 70-75% of 1RM
- • 4 sets of 8-10 reps
- • High volume
Weeks 5-8
- • 80-85% of 1RM
- • 4 sets of 5-6 reps
- • Medium intensity
Weeks 9-12
- • 85-95% of 1RM
- • 3-5 sets of 1-3 reps
- • Maximum intensity
3 Measure your progression
Recalculate your 1RM every 6-8 weeks to track your progress and adjust your loads.
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Beginners
Rapid progression: +10-20 lbs every 2 months on big lifts
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Intermediate
Moderate progression: +5-10 lbs every 2-3 months
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Advanced
Slow progression: +2-5 lbs every 3-6 months
4 Compare your performances
Use strength standards to evaluate your level on basic exercises.
Standards for bench press (176 lbs man):
BenchRep calculates your 1RM automatically
With each recorded set, BenchRep automatically calculates your estimated 1RM and tracks its evolution over time. Visualize your progress with detailed graphs.
Try for freeSafety tips
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Progressive warm-up mandatory
Before testing a 1RM or working heavy, do 3-4 warm-up sets gradually increasing the load.
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Never test alone
For exercises like bench press or squat, always have a spotter to ensure your safety.
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Master technique first
Only test your 1RM if you perfectly master the exercise technique. Poor execution under maximum load = guaranteed injury.
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Prefer estimations
Regularly testing your real 1RM is taxing. Instead use the calculator with sets of 3-5 reps to estimate your maximum strength.
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Respect recovery
Don't test your 1RM more than once every 6-8 weeks. The nervous system needs time to recover.
Frequently asked questions
What formula does the calculator use?
We use the Epley formula: 1RM = Weight × (1 + Reps/30). It's one of the most accurate and widely used formulas in bodybuilding. It's particularly reliable for sets between 1 and 10 repetitions.
Should I test my real 1RM?
It's not necessary to progress. Estimates are accurate enough to program your training. Reserve real 1RM tests for special occasions (competitions) or maximum 1-2 times per year.
Does the calculator work for all exercises?
Yes, but it's more accurate on compound movements (squat, bench press, deadlift, overhead press). On isolation exercises, muscular endurance plays a bigger role and can skew the estimation.
My 1RM isn't increasing anymore, what to do?
This is normal after a few months of training. To break through a plateau: vary your exercises, increase your training volume, optimize your nutrition (caloric surplus) and ensure sufficient recovery. A specific strength cycle (85-95% 1RM) can also help.
How often should I recalculate my 1RM?
Every 6-8 weeks, or after each training cycle. BenchRep does it automatically with every recorded session, allowing you to see the evolution in real-time with no effort.
Ready to maximize your strength?
Download BenchRep and let the app automatically calculate your 1RM with every workout. Track your progression and optimize your loads for maximum gains.
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