One Rep Max Calculator
Calculate Your Maximum Strength
Use this One Rep Max (1RM) Calculator to estimate the maximum weight you can lift for a single repetition based on the number of repetitions you can perform with a certain weight. For the most accurate estimate, please use a weight that you can lift between 1 and 10 times.
Your One Rep Max Results
Estimated 1RM
Weight Lifted
Training Range
Training Percentages
| Percentage | Weight | Training Focus |
|---|---|---|
| 50% | 58.3 KG | Warm-up, technique |
| 60% | 70.0 KG | Explosive power |
| 70% | 81.7 KG | Muscle endurance |
| 75% | 87.5 KG | Muscle growth |
| 80% | 93.3 KG | Strength building |
| 85% | 99.2 KG | Maximal strength |
| 90% | 105.0 KG | Peak strength |
| 95% | 110.8 KG | Competition prep |
| 100% | 116.7 KG | 1RM (estimated) |
Training Recommendations
Explosive Power (50-60% 1RM)
Muscle Endurance (~70% 1RM)
Muscle Growth (70-80% 1RM)
Strength & Power (80-100% 1RM)
Formula Comparison
| Formula | Estimated 1RM | Accuracy |
|---|---|---|
| Epley | 116.7 KG | Most popular, good accuracy |
| Brzycki | 112.5 KG | Widely used, reliable |
| Lombardi | 117.5 KG | Good for powerlifting |
Calculation Details
Understanding One Rep Max
A "one rep max" (one-repetition maximum) is the maximum weight a person can lift for one complete repetition of a specific exercise while maintaining proper form. It is a measure that is commonly used in weightlifting competitions since it represents the peak force that a person's muscles can generate in an all-out effort.
Why One Rep Max is Important
Knowing your one rep max (1RM) is valuable because it provides a quantitative measure of your maximal strength for a given exercise, which enables you to design a workout program and train accordingly based on your goals.
Estimation Methods
This calculator provides three proven formulas for estimating your 1RM:
Most popular formula, provides good accuracy for most lifters.
Widely used in strength training, reliable for experienced lifters.
Good for powerlifting, slightly different approach to estimation.
How to Use This Calculator
- Select a challenging weight: Choose a weight you can lift for 3-10 reps with proper form.
- Perform to failure: Lift the weight until you can no longer complete a repetition with proper form.
- Record your results: Note the weight and number of completed repetitions.
- Calculate your 1RM: Use the calculator to estimate your maximum strength.
Safety Guidelines
- Always use proper form: Form is more important than weight.
- Use a spotter: Especially when attempting heavy weights.
- Warm up properly: Prepare your muscles before testing.
- Don't test 1RM too frequently: Allow adequate recovery time.
- Listen to your body: Stop if you feel pain or discomfort.
Training Intensity Guidelines
- 50-60% 1RM: Explosive power training (3-5 reps)
- 70% 1RM: Muscle endurance (10-15 reps)
- 70-80% 1RM: Muscle growth (7-12 reps)
- 80-100% 1RM: Strength and power (1-3 reps)
⚠️ Important Disclaimer
Always consult with a qualified fitness professional or healthcare provider before engaging in maximal strength testing or starting a new exercise program. Safety should be the top priority when assessing and training for maximal strength. This calculator provides estimates only and should not replace professional guidance.