One Rep Max Calculator

One Rep Max Calculator: Determine Your Lifting Potential

The One Rep Max (1RM) is the maximum amount of weight one can lift for a single repetition of a given exercise. Knowing your 1RM is crucial for designing a strength training regimen and tracking improvements in muscle strength over time.

What is One Rep Max?

1RM stands for One Repetition Maximum. It's the heaviest weight you can lift once, and not more. The 1RM measurement is commonly used to establish the baseline strength in weightlifters and assess the effectiveness of a strength training program.

Different Variations and Formulas to Estimate 1RM

While the most accurate way to determine 1RM is by actually lifting to failure with proper form, there are numerous estimation methods which are safer and less taxing. Here are some of the popular formulas:

Epley Formula:

        1RM = weight + (weight x repetitions x 0.033)
        

Brzycki Formula:

        1RM = weight / (1.0278 - (0.0278 x repetitions))
        

Lombardi Formula:

        1RM = weight x repetitions^0.10
        

Examples Using Different Formulas

If you've benched 100kg for 5 repetitions:

Using the Epley Formula:

        1RM = 100 + (100 x 5 x 0.033) = 116.5kg
        

Using the Brzycki Formula:

        1RM = 100 / (1.0278 - (0.0278 x 5)) = 115.7kg
        

Using the Lombardi Formula:

        1RM = 100 x 5^0.10 = 119kg
        

Why Knowing Your 1RM is Important

Your 1RM serves as a benchmark for:

• Designing a weightlifting program tailored to your strength levels.
• Monitoring your progression in strength over time.
• Setting and achieving strength-related goals.

Caution

It's important to note that lifting near your 1RM, especially without proper warm-up or form, can pose a risk of injury. Always prioritize safety by ensuring you have a spotter or using safety equipment when attempting near-max lifts.

Disclaimer: The above formulas provide estimates. The true 1RM can vary and should be tested in a controlled, safe environment.