One Rep Max (1RM) Calculator
Estimate your maximum lifting capacity to effectively plan your strength training.
What is a One Rep Max (1RM)?
Your One Rep Max (1RM) is the maximum amount of weight you can lift for a single repetition of an exercise. It's a key metric in strength training, as it helps you assess your current strength, track progress, and plan your workouts. By knowing your 1RM, you can calculate the appropriate weight for different rep ranges (e.g., 70% of 1RM for 10 reps) to achieve specific fitness goals like hypertrophy (muscle growth) or endurance.
Our 1RM calculator uses a widely accepted formula (the Epley formula) to provide an accurate estimate without having to attempt a dangerous maximum lift. Simply input the weight you can lift and the number of reps you can complete, and we'll do the rest.
Why Use a 1RM Calculator?
- Safety: Avoids the risk of injury that comes with attempting a true 1RM.
- Progress Tracking: A reliable way to measure and quantify strength gains over time.
- Workout Planning: Helps you determine the right weight for various rep ranges to target different training goals.
For more in-depth information on strength training and 1RM, you can visit authoritative sources such as the National Strength and Conditioning Association (NSCA) and American College of Sports Medicine (ACSM).
Calculate Your 1RM
Frequently Asked Questions
Your One Rep Max (1RM) is the heaviest weight you can lift for a single, complete repetition of a given exercise. It's a fundamental measure of your absolute strength and a benchmark for tracking your progress in a training program.
This calculator uses the Epley formula, a popular and accurate method for estimating 1RM. The formula is: 1RM = Weight × (1 + Reps/30). It provides a safe alternative to a real 1RM test, which can be risky without proper spotters and form.
Knowing your 1RM is essential for structuring a workout program. It allows you to train with a specific percentage of your maximum lift to achieve different goals. For example, lifting at 80% of your 1RM is ideal for building strength, while a lower percentage is better for muscle endurance.
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