How to Find Your 1-Rep Max (Calculator Included!)

Everything you could possibly want to know about 1-rep maxes!

In strength training, a 1-rep max (1-RM) is much more than bragging rights. The idea that a 1-RM is just a number for one maximal lift is short sighted, as it’s much more. A 1-RM is a landmark for quality programming, conditioning, and training.

When it comes to consistent strength training, 1-RMs help dictate multiple training variables and a program’s flow. This provides direction for micro, meso, and macrocycles and helps lifters push their potential from a strategic point of view.

In this article, we’re going to cover everything that goes into establishing a 1-RM and will cover a plethora of topics including:

For the visual learners out there, check out our in-depth video to explain the topics addressed above!

What Is a 1-RM?

A 1-repetition max (1-RM) is the absolute maximum amount that can be lifted for one rep for any given exercise. A true 1-RM will leave nothing in the tank and leaves lifters and athletes with an internal feeling of, “I couldn’t add more weight to the bar if I tried.”

As opposed to only using 1-RMs for compound exercises, a 1-RM can technically exist for any exercise. However, it’s worth noting that not all 1-RMs will carry the same weight when it comes to directing strategic programming. It’s also worth noting that some exercises are simply not worth maxing out due to the risk:reward ratio that comes along with them.

Benefits of Knowing 1-RMs

There are handfuls of benefits that come with knowing your 1-RMs and using them strategically. These benefits will slide and shift based on one’s goals, needs, and overall training status.

1. Better Programming

The first benefit of knowing or having an idea of your 1-RM is that it creates better programming. A great program will be structured to progress strength and adaptations in a strategic way and 1-RMs can help dictate flow of training within: 

  • Macrocycles: Annual or yearly scope of training
  • Mesocycles: 3-8 week blocks that are designed to accommodate various adaptations
  • Microcycles: 1-2 weeks of training that have a very specific focus


Within these timelines, programs will often use auto-regulatory methods like RPE, RIR, velocity based training, and others to dictate training intensities, and 1-RMs can help add depth to the programming of intensities.

For example, a lot of coaches will tie percentages and auto-regulation together to provide the best scope for strategic training, and without knowing one’s 1-RM (whether exact or estimate) it’s impossible to do this accurately.

2. Coaching and Daily Workouts

Another benefit that comes with knowing your 1-RMs is how they help coaches direct training. Whether you program for yourself or for others, 1-RMs can help provide a better lay of the land for where your body or your client’s body is at.

For example, if someone is feeling burnt out and they don’t know their 1-RMs for various training days, then likely they’re haphazardly pushing too high of intensities too often, which is less than ideal for longevity in the gym. This is where circling back to the first benefit of using 1-RMs to create better programs with auto-regulation comes into play.

Who Should Know Their 1-RM?

While knowing 1-RMs is important for direction of programming, it’s not exactly needed for everyone. So who needs know their true 1-RM?


For most true beginners, knowing their 1-RMs isn’t incredibly important because building a foundation of strength and form should take precedence. Note, having a loose idea can be useful, but truly maxing out before mechanical proficiency is dialed in could be counterproductive.


Intermediate lifters can benefit from knowing their 1-RMs, however, it’s worth acknowledging that intermediate training ages can be defined by a pretty wide range. Considering this can help direct which type of 1-RM testing will be most beneficial (more on those below).

  • Intermediates that don’t have ambitions for ever testing their true 1-RM strength or competing can simply use calculations to best direct their training and intensities.
  • Intermediates that want to compete and push themselves can benefit with knowing and testing their true 1-RMs or using calculations.

Advanced and Sport Athletes

Advanced lifters and athletes can absolutely benefit with knowing their 1-RMs, and this is a no-brainer. Strength athletes need to know their 1-RMs to program accordingly for competition and to create realistic goals. Generally, true 1-RMs will be the best bet for this type of lifter.

Sport athletes will likely not need to test or know their true 1-RM and can get away with using a heavy double or triple to help dictate their projected 1-RM. The risk:reward usually isn’t there for elite sport athletes and heavy doubles and triples that are regularly programmed can suffice just fine for estimated 1-RMs.

How to Find Your 1-RM

There are a couple ways to find 1-RMs and each method should be chosen based on a few different factors:

  • Training Age
  • Goals
  • Individual Needs

This circles back to the point above when we referenced that true beginners can likely benefit better using calculations compared to truly maxing out lifts.

1. Max Out Days

The first method for finding your 1-RM is with a 1-RM resting day. These are days where there’s one goal in mind and that’s maxing out a desired lift or lifts.

For true 1-RM testing days, there are a couple requirements that will set you up best for success and these include:

  • Structure to your 1-RM testing day with programming that preps the body and mind. A couple useful questions to consider include:
    • What lifts do you plan on maxing out? Are you splitting up lifts across multiple max out days?
    • Is your warm-up dialed in and adjusted to prep the body for maximal intensities?
  • Spotters and proper equipment.

Outside of the baseline requirements that are a good idea to have for 1-RM testing days, there are also pros and cons that come along with these days. 

1-RM Testing Pros

  1. Provide the most accurate idea for where one’s 1-RM is sitting.
  2. Can stand longer than calculations and add even more accuracy to programming.
  3. Increase experience under the bar when moving weight at this caliber.

1-RM Testing Cons

  1. Very mentally and physically draining, account for this before programming them!
  2. Spotters and the proper equipment are a must have.

1-RM Testing Tips

Every coach and athlete will have their own list of tips and processes for structuring 1-RM testing days. Below, we’ve provided some of our favorite tips to keep in mind when maxing out!

1-RM Testing Tips
1-RM Testing Tips

Related: Check out Ben Pollack’s awesome article on testing 1-RMs like a pro!

2. 1-RM Calculators

Another popular and much more beginner/intermediate-friendly way to find 1-RMs is with the use of 1-RM calculators. This a great option for beginners and intermediates because they can provide a baseline level for directing training and programming.

For those interested in using 1-RM calculators to establish an estimate for their 1-RM the requirements are much lower:

  • Knowledge of a few heavy double, triple, or four rep sessions for a desired lift.
    • Reality is, you only need one number, but having a few numbers to pull from can increase accuracy, but more on that below.

Much like max out days, 1-RM calculators come with their own list of pros and cons. Check them out below.

1-RM Calculator Pros

  1. Easy to use and accessible for everyone.
  2. Can provide training direction for populations that are not yet ready to fully max out.

1-RM Calculator Cons

  1. Not as accurate as truly maxing out.

When it comes to 1-RM calculators there are multiple equations that are used, but the two most popular tend to be the Brzycki and Baechle formulas. 

1-RM Calculations
1-RM Calculations

Related: How beginners, intermediate, and advanced lifters can find their 1-RMs.

1-RM Calculator Tips

Despite calculators being easy to use for everyone, there are a few tips to keep in mind when using them.

Remember, a calculator can always have some discrepancy when it comes to accuracy, so using the tips below can ensure you’re obtaining the best estimate for your 1-RM. 

1-RM Calculator Tips
1-RM Calculator Tips

The goal with calculators is to find an average and use that to direct training, as this will provide more accuracy.

1-RM Calculator

To test your 1-RM, check out the BarBend 1-rep max calculator below!

One Rep Max Calculator

Weight Lifted
Reps Performed


What is a 1-rep max?

A 1-repetition max (1-RM) is the absolute maximum amount that can be lifted for one rep for any given exercise.

Does everyone needs to know their 1-RM?

Not necessarily. While knowing 1-RMs can be useful for intermediate and advanced lifters to provide accuracy for programming, beginners don’t necessarily need to know their true 1-rep max strength.

Why do I need to know my 1-rep maxes?

Technically no one needs to know their true 1-rep maxes, however, at least having an idea can provide multiple benefits including:

  • Strategic programming
  • More self awareness
  • Improved levels of coaching

Concluding Thoughts

Knowing your 1-RM can be an incredibly tool for improving programming and energy towards goals. When finding your 1-RM, it’s important to remember that not every method is created equal and to select the 1-RM testing means that match’s your individual needs best!