What is a One Rep Max (1RM)?

A One Rep Max (1RM) is the maximum amount of weight that an individual can lift for a single repetition of a given exercise with proper form. It is a crucial metric in strength training and weightlifting, serving as a benchmark for an individual’s strength in specific exercises such as the squat, bench press, or deadlift.

The 1RM is used to gauge progress, set training goals, and determine appropriate weights for various training intensities.

How to Use the One Rep Max Calculator?

1. Enter the Weight: Input the weight you’ve lifted in the “Weight lifted” field. This can be in pounds (lbs) or kilograms (kg). The calculator will automatically detect the unit based on the magnitude of the number (if it’s 100 or above, it assumes pounds; otherwise, it assumes kilograms).

2. Input the Repetitions: Enter the number of repetitions you performed with the given weight in the “Number of repetitions” field. This should be a number between 1 and 30.

3. Calculate: Click the “Calculate 1RM” button to generate your results. The calculator will display your estimated One Rep Max, along with a brief explanation of what this means. This estimate is based on the Epley formula, which is widely used and respected in strength training circles.

4. Review the Percentage Table: Below the main result, you’ll find a table showing various percentages of your 1RM. This table is particularly useful for planning your training regimen:

• The “Percentage” column shows different intensity levels, from 100% down to 50% of your 1RM.
• The “Weight” column displays the corresponding weight for each percentage.
• The “Reps” column provides a general guideline for the number of repetitions you might be able to perform at each intensity level.

5. Use the Information: You can use these percentages to plan your workouts. For example:

• For maximum strength training, you might work with weights at 90-95% of your 1RM for low repetitions.
• For hypertrophy (muscle growth), you might use weights at 70-85% of your 1RM for moderate repetitions.
• For muscular endurance, you could use weights at 50-65% of your 1RM for higher repetitions.

Though this calculator provides a good estimate, it’s not a substitute for actual testing under proper supervision. Always prioritize safety when attempting heavy lifts, and consider working with a qualified strength coach or trainer, especially when approaching your true 1RM.