1. What is 1 Rep Max (1RM)?

The 1 Rep Max (1RM) is the maximum amount of weight you can lift for one repetition of a given exercise. It's a standard measurement used to assess strength and to determine appropriate training weights.

2. How Does the Calculator Work?

The calculator uses the ExRx 1RM equation:

Where:

• \( Weight \) — The weight lifted (kg or lbs)
• \( Reps \) — The number of repetitions performed (1-20)

Explanation: This equation estimates your one-repetition maximum based on how much weight you can lift for multiple repetitions. The formula accounts for the nonlinear relationship between repetitions and maximum strength.

3. Importance of 1RM Calculation

Details: Knowing your 1RM helps in designing effective strength training programs, tracking progress, and setting appropriate weights for different training goals (endurance, hypertrophy, or strength).

4. Using the Calculator

Tips: Enter the maximum weight you can lift for a given number of repetitions (between 2-20 reps). For most accurate results, use a weight that brings you to failure within 2-10 reps.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is the 1RM estimation?
A: The formula provides a good estimate (±5-10%) for most people when using rep counts between 2-10. Accuracy decreases with higher rep ranges.

Q2: Should I actually test my 1RM?
A: For beginners or those without proper supervision, it's safer to estimate. Experienced lifters with proper technique and spotters can perform actual 1RM tests.

Q3: Does this work for all exercises?
A: The formula works best for compound lifts like bench press, squat, and deadlift. Accuracy may vary for isolation exercises.

Q4: How often should I calculate my 1RM?
A: Every 4-8 weeks for most trainees, as strength changes over time with training.

Q5: Are there other 1RM formulas?
A: Yes, other popular formulas include Brzycki, Epley, and Lombardi. ExRx formula is one of the most commonly used.