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

The 1 Rep Max (1RM) is the maximum amount of weight you can lift for one complete repetition of a given exercise. For bench press, it's a common measure of upper body strength.

2. How Does the Calculator Work?

The calculator uses the following equation:

Where:

• \( weight \) — Weight lifted in pounds (lb)
• \( reps \) — Number of repetitions performed (count)
• 0.0333 — Constant factor for estimation

Explanation: This formula estimates your one-rep maximum based on how many reps you can perform with a submaximal weight.

3. Importance of 1RM Calculation

Details: Knowing your 1RM helps in designing strength training programs, tracking progress, and setting appropriate weight loads for different training goals.

4. Using the Calculator

Tips: Enter the maximum weight you can lift for multiple reps (typically 2-10 reps) and the number of reps you performed. All values must be valid (weight > 0, reps between 1-20).

5. Frequently Asked Questions (FAQ)

Q1: How accurate is this estimation?
A: The formula provides a good estimate but actual 1RM may vary by ±5-10% depending on individual factors.

Q2: What's the best rep range to use for estimation?
A: 3-8 reps provide the most accurate estimates. Higher rep ranges (10+) may overestimate true 1RM.

Q3: Should I actually test my 1RM?
A: For beginners, estimation is safer. Experienced lifters can test 1RM with proper warm-up and spotting.

Q4: Does this work for other exercises?
A: While designed for bench press, it can estimate 1RM for other lifts though accuracy may vary.

Q5: How often should I recalculate my 1RM?
A: Every 4-8 weeks as your strength changes, or whenever you can do more reps with the same weight.