1 Rep Max Calculator + Online Solver With Free Steps

The 1 Rep Max Calculator is a free online tool that calculates the maximum weight that can be lifted for a single repetition of a certain exercise.

A one rep max calculator is crucial for estimating one’s capacity on the squat rack, bench, deadlift, and more to lift safely.

1 rep max calculator

What Is a 1 Rep Max Calculator?

The 1 Rep Max Calculator is a calculator that determines the maximum amount of weight a person can lift during a single repetition of an exercise when using good form and a full range of motion.

One approach to gauge your strength is to look at your single repetition maximum (1RM), which is the largest weight you can lift. It might be compared to a runner’s VO2 max.

One-rep maximums can be tested in reality by simply raising the weight of the barbell, although this approach isn’t advised for everyone, especially beginners and those with little expertise due to the risk of injury.

Luckily, it is possible to forecast your maximal lift if you can complete a particular number of repetitions with a smaller weight.

How To Use a 1 Rep Max Calculator?

You can use the 1 Rep Max Calculator by following the detailed step-by-step instructions provided; the calculator will undoubtedly provide you with the desired results. Therefore, you can follow the guidelines provided to determine the maximum weight that a person can lift.

Step 1

Fill in the provided input boxes with Weight Lifted and the number of repetitions.

Step 2

When you click the “SUBMIT” button, the total step-by-step solution for the 1 Rep Max will be presented along with the value of the maximum weight one may lift.

How Does the 1 Rep Max Calculator Work?

The 1 Rep Max Calculator works by using Jim Wendler’s formula to compute one rep max. It is difficult to determine your single repetition maximum because numerous elements affect body performance.

There are numerous formulas, some of which provide more accurate results than others, but each one should be used with caution. One-rep maximum calculator employs two techniques:

The Epley Formula

The Brzycki formula and this one rep maximum formula have both been around since the turn of the century and have both shown to be extremely accurate. The formula looks like this:

\[ 1RM = weight \times (1 + (\frac{number\; of \; reps}{30})) \]

It’s designed to work for any lift, but since your squat maximum is probably larger than your bench press maximum, you might want to make your adjustments.

The NSCA Exercise Specific Coefficients

The National Strength And Conditioning Association proceeded one step further and created a list of coefficients to multiply by the weight depending on how many repetitions were performed.

They take into account the fact that your maximal lift varies according to the type as each one targets a distinct set of muscles. The NSCA criteria include:

Number of repetitionsSquatDeadliftBench press

No matter how you determine your rep maximum, bear in mind that the outcome is more accurate the fewer repetitions.

For instance, it’s preferable to determine your one-rep maximum using the weight used in a set of three rather than eight if you want to test your squat maximum.

Percentage of One Rep Max 

It may be helpful to plan your workouts with an understanding of your limitations, but the percentage you should utilize will depend on your aim. The following are typical areas of use:

Explosive power: 50% of 1RM

Even though many people might not be familiar with this phrase, it’s fairly simple. Consider an explosion; it occurs quickly and releases a tremendous quantity of energy.

As a result, having explosive power in sports refers to your capacity to use all of your strength in a short period. You’ll train your muscles to produce power without growing too big and sluggish.

Endurance: 70% of 1RM

Endurance is the ability of a muscle (or group of muscles) to continue contracting for an extended amount of time.

Simply put, you can move for longer if your endurance is higher. Most repetitions are used during this sort of exercise, which also boosts your metabolism for a few hours.

Hypertrophy: 80% of 1RM

Hypertrophy is a scientific term used to describe the growth of muscle mass. Bodybuilders typically strive for this proportion.

Power: 90% of 1RM

It is important to note that this style of training does not involve explosive movements; rather, it involves lifting large weights quickly to exert maximum force.

Strength: 95% of 1 RM

The quickest way to raise your one-rep maximum is by doing this, but you shouldn’t go too far.

Keep the repeats between 1 and 3, and ideally, have a watchful eye nearby (a so-called spotter). Setting a new bench press maximum is pointless if the barbell smashes your internal organs.

You can get the percentage that is acceptable for your objective without making any further calculations thanks to the one rep max chart that is also available on our online calculator.

Ways To Increase One-rep Max

Numerous people begin exercising to improve themselves, however, in addition to how to raise one-rep max, another issue comes up:

How can you go about it healthily? The most important elements that could have an impact on your performance are listed below:

  • The most obvious way to get fitter is through regular exercise. You want to put forth a lot of effort while remaining wise.

Reaching your objective should be simpler now that you know the answer to the question, “What percentage of my one-rep max should I lift?” However, since safety should always come first, we always advise seeing a professional if in doubt.

  • It might come as a shock, but getting enough rest is as crucial. If you put too much stress on your body, you won’t obtain the results you want; your muscles get stronger once you recover from exercise.

The correct amount of sleep is very crucial. Knowing your one-rep maximum is useless if you can’t reach the desired % because your body is working too hard.

  • Since food essentially serves as your fuel, it’s important to maintain a healthy diet. If you’re simply a casual gym goer, you don’t need to calculate your macros, but understanding your suggested calorie intake may be useful.

If it requires too much work, attempt to at least get enough protein, which is essential for gaining lean muscle mass and may hasten recuperation.

  • On the other hand, drinking alcohol could hurt your athletic performance. In addition to dehydrating you, it can also interfere with your recuperation, cause weight gain, and impact your growth hormone.

Solved Examples

Let’s look at a few instances to better understand how the 1 Rep Max Calculator operates.

Example 1

Make use of these formulas to determine your 1RM.

Fill in this equation with the heaviest weight you can lift four to six times:

=(4.6RM x 1.1307) + 0.6998 

Note: If your value is given with a decimal point. Round it up, go ahead.


Therefore, if you can perform 5 repetitions of 60 kg, then using the formula

(60 x 1.1307) + 0.6998 

Your 1RM will be 68.5kg.

For the lower body use this formula:

(4-6RM x 1.09703) + 14.2546 

Now that you are aware of your 1RM, you may select the volume and intensity of your workout to best meet your training objectives.

Example 2

Calculate the 1 RM for the given data.


Estimated 1 RM = Weight x Reps x 0.0333 + Weight.

Therefore, your predicted 1 RM is if you bench 225 x 6 times.

 225 x 6 x 0.0333 + 225 = 270

Once more, your “theoretical” bench max is 270 if you can press 225 for 6 repetitions.

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