One Rep Max Calculator
Calculate your maximum lift weight for strength training & program design
What is One Rep Max (1RM)?
1RM is the maximum weight you can lift for one complete repetition with proper form. This calculator estimates your 1RM from submaximal lifts (3-12 reps) using proven formulas like Epley, Brzycki, and Lander – perfect for programming workouts and tracking progress.
How to Use
- Select your exercise type and recent performance.
- Enter the weight lifted and number of reps completed.
- Choose calculation formula (Epley recommended for most).
- Get your estimated 1RM and training percentages instantly.
FAQs
- Which formula is most accurate?
- Epley works best for 3-10 reps. Brzycki good for higher reps. Test actual 1RM for precision.
- Is this safe for beginners?
- Use conservative estimates (5-10% below calculated 1RM) until experienced with the lift.
- How often should I test 1RM?
- Every 8-12 weeks max. Use submaximal testing more frequently to avoid injury.
- Does fatigue affect accuracy?
- Yes – test when fresh. Recent heavy sessions reduce performance 5-15%.
- Should women use different formulas?
- Same formulas work. Women typically have 50-60% upper body 1RM vs men, similar lower body.
