1RM CALCULATOR Featured Image

1RM Calculator

The 1RM calculator is an excellent piece of software that is necessary to use for various reasons. 

Some of them include planning your workouts, the intensity, rep ranges, the number of sets, and more. In addition, if you want to train for hypertrophy, strength, or power, you will need to use different percentages of your 1RM. 

Keep reading below to learn everything you need about 1RM calculators, why they are useful, how to use them for your workouts and more.

Quick Summary

  • One rep max calculator is a tool that tells how much weight you can lift for only one repetition, resulting in your maximum force output for a specific exercise.
  • 1RM can be improved with numerous methods, but the most important one is the principle of progressive overload.
  • You can use the information from one rep max calculator to program your workouts based on your fitness goals.

What Is One Rep Max Calculator?

A one rep max calculator is software used to calculate the maximum weight you can lift for a single repetition of a given exercise. It is used for various reasons, one of which is determining the rep range and the number of sets.

One rep max is a crucial factor in the fitness community that is heavily used to determine the load you are going to use during your workouts. For example, to build strength, it is necessary to use more than 80% of your 1RM. 

But how can you know your one rep max without actually trying to lift the maximum amount of weight? 

That's where one rep max comes into play. It is enough to know, for example, what is the maximum amount of weight you can lift for a certain exercise for six reps. Afterwards, you can plug that information into the calculator that will tell you, based on the input, how much is your one repetition max.

Repetition Percentages of 1RM





















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How Do I Test My One-Rep Max?

You test your one-rep max by completing a percentage-based program based on one rep max. Fitness professionals with sufficient knowledge of screening often execute these testing programs. 

Coaches and trainers are the ones setting up programs with percentages based on your one repetition max. The reason why they do that is to collect the necessary data which is going to be used for workout programming. 

Here are some things to remember when putting information in a one-rep max calculator:

  • One-rep max calculator gives the most precise results when you enter a lower number of reps. For example, the four rep max will give a better estimate than a 12 rep max.
  • You should always stop your set when you compromise exercise form, meaning that is the number you are going to put in the calculator. In addition, no one rep max test is worth getting injured.
  • You should remember that there will be slight changes according to the exercise you choose to know your 1RM. Strength is highly specific, and you shouldn't program your front squat repetitions and sets based on the 1RM back squat testing.
  • All these things are essential to avoid injuries, get the most accurate information, and program your workouts correctly.

What Percentage of My One-Rep Max Should I Lift?

What percentage of your one-rep max you should lift will highly depend on your personal goals. There is a different rep range for hypertrophy, strength, power, and endurance.

For endurance, you should complete as many repetitions as possible with as little rest between the sets. Approximately you should aim to do more than 12 repetitions and have less than 30 seconds of rest between the sets.

For hypertrophy, you will pick moderate weight. Rep range is between 6 and 12, number of sets 3-4, and less or equal to 90 seconds of rest between the sets.  If you're looking to optimize your hypertrophy training, considering the best hypertrophy program can be beneficial.

For strength, you will always have to fully recover before completing the next set. Generally, you should aim to do less or equal to 5 repetitions per set, complete 3-4 sets, and rest between 3-5 minutes or as much as you need to repeat the same effort. Incorporating strength and conditioning workouts into your routine can further enhance your overall performance and results.

Lastly, for power, it is almost the same as for strength. You should aim for as few as one repetition, usually up to 3, and rest as much as you need between the sets so that you can repeat the same effort again.

How Do I Use My One-Rep Max in a Workout?

To use your one-rep max in a workout, you should program your workouts based on it.

For example, use your one rep max to calculate how much weight you can lift for 20 reps to increase endurance.

This is only a suggestion, but you can use your 1RM in so many other ways. You can even compare the push-pull ratio of 1RM to see if you developed any muscle imbalances.

For example, your pull-up 1RM should be approximately 80% of your flat bench 1RM.

This will ensure the balance between your agonist and antagonist's muscles and develop your body holistically without any problems with the posture later on. 

You can also use your 1RM to compare it to the specific lifting standards so that you know how much you must improve.

4 Ways to Increase Your Bench Press Max

The bench press is a compound horizontal push exercise primarily used to develop your upper body musculature. If you're wondering what muscles does the bench press work? it targets several key areas of the upper body. 

It is not a secret many seek to increase their bench press by one rep max, so I compiled a list of useful tips to guide you along the way. Here are the four ways to increase  your bench press 1RM:

Lift with proper form

To lift properly, you should hold a neutral position of your spine on the bench. This means you shouldn't push your back into the bench or overarch it.

Your feet should have a firm hold on the ground and help you during the concentric or lifting phase of the bench press. 

Also, you should inhale and create intraabdominal pressure, which will help you during the lifting phase.

Always aim to complete the exercise through a whole range of motion since you don't want to create weaknesses in any spot of your bar trajectory towards your chest.

Use progressive overload

Progressive overload is the principle that emphasizes progressing the exercise in a specific way.

For example, to increase your bench press 1RM, you should probably cover the hypertrophy phase first, which consists of more reps and lesser external resistance.

After the hypertrophy phase ends, you should progress by lowering the number of repetitions but increasing the load. This is what progressive overload essentially is.

To progress, you should tweak the number of reps, sets, external loads, and even rest periods. For strength, progress by lowering the number of reps, increasing the load, and resting as much as needed.

Use different set formats

Set formats can be pyramids, supersets, contrast training, and similar. To increase your bench press 1RM, I suggest trying the above mentioned tactics first.

However, during a hypertrophy phase that precedes the strength phase, you can use pyramid sets and supersets to induce the effects of hypertrophy faster.

Strengthen your synergists

Synergists are muscles that help the movement and aid in the total strength of the prime movers. Prime movers are also agonists, or muscles which initiate the movement.

For example, the prime movers of bench press are pectoralis major, triceps brachii, and anterior deltoid. However, synergists that help complete the bench press movement include muscles such as serratus anterior and shoulder blade muscles.

By isolating these muscles, you can efficiently produce more force during the bench pressing, resulting in a bigger 1RM.

How to Warm Up for a 1RM Attempt?

To warm up for a 1RM attempt, you should complete a dynamic warm-up followed by the progressive overload of the desired exercise. This will ensure you avoid injury and get the most out of your 1RM.

A dynamic warm-up can include as little as 3 minutes of running, followed by shoulder external rotator activation.

Just take a band or small weight and do a couple of sets of external shoulder rotations to prepare them for the lifting.

After that, start bench pressing with as little as 50% of your 1RM and slowly progress by adding load until you eventually reach your 1RM.

What’s the Difference Between 1RM and PR?

The difference between 1RM and PR is that PR is the heaviest weight you have ever lifted, while 1RM is the heaviest weight you can currently lift on a specific exercise.

Both one-rep max and personal records are useful for programming workouts, planning intensity, and deciding upon rest intervals. In addition, the peak of your one rep max during a certain period, let's say over a year, will become your PR.

After that, you will need to downgrade your performance purposefully so that you can come back stronger next time. This is the principle of conditioning, which says you can't always be in the top form, but rather cycle it during a macrocycle.

How to Increase Your 1RM?

To increase your 1RM, you should use a progressive overload principle coupled with proper form and recovery. These will ensure maximum performance and increase in your 1RM.

Progressive overload is simply progressing in a specific metric in your workouts. You can progress the number of reps, sets, and external load or decrease the rest time.

Also, you can increase the number of training sessions per week. 

Proper form will ensure you develop strength through the full range of motion without getting injured. Also, a proper form is always the best option for longevity and long-lasting results. Never sacrifice your exercise form to lift more weight.

Recovery consists of sleep, proper nutrition, and supplementation.

There are alternative recovery ways, but the previously mentioned ones are the most important. Among those three, sleep and proper nutrition or diet are the ones that will increase your 1RM the most.


How Accurate Is a One-Rep Max Calculator?

One-rep max calculator is very accurate. However, the one rep max calculator tends to be more accurate when inputting a lower number of repetitions.

How to Calculate One-Rep Max for Deadlift?

To calculate one-rep max for deadlift, multiply your 4-6RM with 1.1307 and add 0.6998. The number that comes out is the closest to your deadlift 1RM.

How Much Should Your One-Rep Max Be?

How much your one-rep max should be will depend on your personal goals. Also, there are different weight standards and 1RM standards that are specific to different exercises.

Why Is 1RM Calculator Important for Your Workouts?

A 1RM calculator is important for your workouts because it helps you program them more efficiently to achieve your personal goals.

You can use your 1RM to determine how many reps you can do with the desired amount of weight.

Lastly, having a larger 1RM is all right but not necessary if you aren’t a competitive Olympic weightlifter, powerlifter, or similar.