The Legion Strength Level Calculator estimates what your one-rep max should be on the main compound exercises, given your experience level. It also predicts how strong you can get in your lifetime without taking steroids.

You can use this data in the following ways:

  1. To set realistic yet challenging goals.
  2. To understand your strengths and weaknesses.
  3. To see how much progress you’ve made since you began lifting weights.
  4. To estimate your natural strength potential.

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How Tracking Your One-Rep Max Helps You Build Muscle

The most reliable way to gain muscle is getting stronger.

As your one-rep max is simply the maximum amount of weight you can lift for a single repetition for a particular exercise, it’s an excellent way to determine whether or not you’re getting stronger. In other words, your one-rep max is a rough proxy for muscle growth.

The relationship between muscle gain and strength isn’t perfect and doesn’t work well for comparing progress between two different people, though. For example, just because one person has a higher bench one-rep max than another doesn’t mean they’ll necessarily have a bigger chest, as other factors also influence muscle growth.

What you can count on is that if your one-rep max is going up for a particular exercise, you’re also growing the muscles that are trained by that exercise.

How to Improve Your One-Rep Max

You can improve your one-rep max in many ways. The simplest method is to follow a well-designed training program that emphasizes progressive overload, like Bigger Leaner Stronger or Thinner Leaner Stronger.

Beyond that, focus on the following:

  • Practice: The best way to get stronger at an exercise is to practice that exercise—you improve your squat strength by squatting, your overhead press by overhead pressing, and so forth. Thus, if you currently bench just once weekly and want to improve, try benching more frequently. 
  • Build muscle: As a new weightlifter, you’ll find most strength gains come from honing your technique. However, as you become more experienced (after 1-to-2 years of consistent weightlifting), building more muscle is one of the most effective ways to increase your one-rep max strength. If you want a program designed to help experienced weightlifters build muscle and get strong, check out my fitness book Beyond Bigger Leaner Stronger.
  • Train with heavy weights: You must regularly train with weights near your maximum to improve your one-rep max strength. A good guideline is to spend approximately 80% of your gym time training in the 4-to-6 rep range (85-to-90% of your one-rep max) and the remainder training in the 6-to-8 or 8-to-10 rep range (75-to-85% of your one-rep max).