One Rep Max Calculator
Calculate your 1RM for any exercise safely and accurately.
What is One Rep Max?
Your 1RM is the maximum weight you can lift for one complete repetition. This calculator estimates it safely using submaximal lifts.
Your 1RM is the maximum weight you can lift for one complete repetition. This calculator estimates it safely using submaximal lifts.
Results
Enter your lift details to see your estimated 1RM here.
Training Percentages
- 50-60% (Light/Speed)
- 70-80% (Hypertrophy)
- 85-95% (Strength)
Related Health Tools
Understanding One Rep Max
One Rep Max (1RM) is the maximum amount of weight you can lift for one complete repetition of a given exercise with proper form. It's a key metric in strength training and powerlifting.
Common 1RM Formulas
- Epley Formula: 1RM = weight × (1 + reps/30)
- Brzycki Formula: 1RM = weight / (1.0278 - 0.0278 × reps)
- Lander Formula: 1RM = weight / (1.013 - 0.0267123 × reps)
- O'Conner Formula: 1RM = weight × (1 + 0.025 × reps)
Why Calculate Instead of Test?
- Safety: Reduces injury risk from maximal attempts
- Recovery: Less fatigue than actual max testing
- Frequency: Can be calculated regularly without overloading
- Programming: Helps set training loads and progression
- Monitoring: Track strength gains over time
Using Your 1RM for Training
| Training Goal | % of 1RM | Rep Range |
|---|---|---|
| Power/Speed | 30-60% | 1-6 reps |
| Strength | 80-95% | 1-5 reps |
| Hypertrophy | 65-85% | 6-12 reps |
| Endurance | 50-70% | 12+ reps |
Best Practices for 1RM Testing
- Use 3-8 Rep Range: Most accurate for calculations
- Fresh Testing: Test when well-rested, not fatigued
- Proper Form: Maintain technique throughout all reps
- Regular Updates: Recalculate every 4-6 weeks
- Exercise Specific: Each lift has its own 1RM
Exercise-Specific Guidelines
Big Three Lifts
- Squat: Use 3-5 rep tests for accuracy
- Bench Press: 2-6 reps work well
- Deadlift: 1-5 reps recommended
Accessory Exercises
- Overhead Press: 3-8 reps ideal
- Rows: 5-10 reps typical
- Isolation: Higher rep ranges (8-15)
Frequently Asked Questions
Calculators are typically within 5-10% of actual 1RM when using 3-8 rep ranges. Accuracy decreases with very high rep ranges (15+). Individual factors like training experience and muscle fiber type affect accuracy.
Yes, but beginners should focus on form first. Use 8-12 rep ranges for calculations and avoid actual 1RM attempts until 6+ months of consistent training. Priority should be on technique and gradual progression.
Calculate estimated 1RM every 4-6 weeks to track progress. Actual 1RM testing should be done sparingly (2-4 times per year) due to the high fatigue and injury risk associated with maximal attempts.