One Rep Max Calculator
Calculate your 1RM to optimize training intensity
Input Training Data
What is 1RM (One Rep Max)?
1RM (One Repetition Maximum) is the maximum weight you can lift for a single repetition with proper form. It is an important indicator of muscular strength.
Why is 1RM Important?
- Training Baseline: Provides scientific basis for determining training intensity
- Progress Tracking: Evaluate training effectiveness and strength gains
- Goal Setting: Set quantifiable training goals
- Safe Training: Avoid using weights that are too heavy or too light
How to Calculate 1RM?
This calculator uses the Epley Formula, a widely used empirical formula:
1RM = Weight × (1 + Reps / 30)
For example: If you can lift 60kg for 8 reps:
1RM = 60 × (1 + 8/30) = 60 × 1.267 = 76kg
Training Zone Divisions
Strength Zone (85-100%)
Increase maximum strength, use 1-5RM weight, rest 3-5 minutes between sets
Hypertrophy Zone (70-85%)
Promote muscle growth, use 6-12RM weight, rest 2-3 minutes between sets
Endurance Zone (60-70%)
Enhance muscular endurance, use 15-20RM weight, rest 1-2 minutes between sets
Warm-up Zone (40-60%)
Activate muscles before training, prevent injury, prepare for main training
Safety Considerations
- Progressive: Start with 60-70% intensity initially and adapt gradually
- Proper Form: Maintain correct exercise form, consult a coach if necessary
- Protection: Use protective equipment or find a partner for heavy lifts
- Regular Testing: Re-test 1RM every 8-12 weeks and adjust training plan
- Listen to Body: Stop training immediately if you feel pain or discomfort
Frequently Asked Questions (FAQ)
1. Do I need to actually test my 1RM?
No. This calculator estimates your 1RM based on a weight you can complete for multiple reps. This is safer than directly testing 1RM, especially for beginners. The optimal range is using a weight you can complete for 2-10 reps.
2. How accurate are the results?
The Epley formula has an accuracy of about ±5-10%, but individual variations exist. For trained athletes, the calculated value may be slightly low. We recommend using the calculated value as a starting reference point and fine-tuning during actual training.
3. How should beginners use 1RM?
Beginners should use 60-70% of their 1RM for the first 4-6 weeks, focusing on learning proper form. After becoming proficient with the movement, gradually increase to 70-80% intensity for hypertrophy training. Don't rush to use heavy weights; form is more important than weight.
4. How often should I test my 1RM?
We recommend re-evaluating every 8-12 weeks or after completing a training cycle. Frequent 1RM testing increases injury risk and affects normal training progress. Using this calculator allows for safer strength tracking.
5. Is the 1RM the same for different exercises?
No. Each exercise has its own 1RM. Typically, compound movements (squats, deadlifts, bench press) will have a higher 1RM than isolation exercises. We recommend calculating 1RM for major training movements separately to create more precise training plans.
Use our 1RM calculator to scientifically plan training intensity and safely improve strength and muscle mass. Based on the professional Epley formula, suitable for fitness enthusiasts of all training levels.