One Rep Max Calculator

powerlifter about to attempt 1RM

One Rep Max Calculator

Learn your estimated one-rep max (1RM) using the calculator below to target your strength goals more effectively.

Finding 1 rep max can be helpful for understanding your current strength level, building programs, and even more! Find yours below!


Repetition Percentages of 1RM

RepetitionsPercentage of 1RM
1100%
297%
394%
492%
589%
686%
783%
881%
978%
1075%
1173%
1271%
1370%
1468%
1567%
1665%
1764%
1863%
1961%
2060%
2159%
2258%
2357%
2456%
2555%
2654%
2753%
2852%
2951%
3050%
Find your estimated 1RM above!

Why Check Your One Rep Max (1RM)?

The primary reason to test and calculate your one rep max is to find your strength level. Whether you are curious where you stack up against other lifters, trying to increase your strength, or just want to know how much you can really bench. You can test your strength level with a one rep max attempt or use a calculator like this to find your estimated 1RM.

Knowing Your Strength Level Using One Rep Max Isn’t the Only Reason

Knowing your one rep max isn’t just important for tracking strength increases. It can be used to achieve all training goals more efficiently and affectively. Your one rep max can be used to train for strength, size, and power.

This is why training programs are frequently set up with percentage-based lifts. The percentages are based on your one-rep max because the program does not know your strength level. They do know what percentage, relative to the 1RM, you should be using on that lift, though.

Testing for your one rep max shouldn’t be done frequently though, as it is very hard on the body. The good news is that there are great ways to estimate it that don’t require lifting your actual one rep max. For example: the calculator above.

Calculate your 1RM’s, then jump on to a training program to use them to grow!

Learn more about one rep max calculator accuracy here or read our own article about it.

How to Test One Rep Max.

When using a 1RM calculator like the one above: the lower the number of reps achieved, the more accurate your estimated 1RM will be. For example, if you enter a weight you got three reps on, it will be more accurate of a calculation than a weight you got 12 reps on.

When testing for an estimated 1RM, stop when form breaks down. Injuring yourself trying to get a higher max will be counterproductive to your long term goals.

Similar lifts will not have the same one rep max. Don’t calculate for bench and then try to use that max for incline bench.

If you want to know your true max rather than your estimated one rep max use the method below.

NASM 1RM Conversion Chart PDF

From the NASM website.

How to Calculate Your One Rep Max Using Our Calculator

Learn how to quickly and accurately estimate your one rep max with our easy-to-use calculator tool! Save time and begin maximizing your workouts today.

Looking to boost your strength and performance? Use our one rep max (1RM) calculator to accurately estimate how much weight you can lift for one complete repetition. This tool takes into account your current strength level, and helps you build an effective training program to reach your fitness goals.

What is a One Rep Max?

One rep max (1RM) is the highest amount of weight that you can lift for one complete repetition. It’s an important measure in strength training, as it helps determine how much load you can move and the intensity of your workouts. Knowing your 1RM can help you build an effective weightlifting program.

How Does Our Calculator Work?

Our calculator uses a customized equation to accurately determine your 1RM from the amount of weight you can lift for multiple reps. All you have to do is provide the weight and number of repetitions for an exercise, and our calculator will instantly generate your 1RM. It’s as simple as that!

Which Factors Can Affect Your Estimate?

While our calculator does its best to accurately estimate your 1RM, there are certain factors that can affect the accuracy of your 1RM predictions. For example, the neuromuscular exhaustion of the muscle due to fatigue, as well as variations in technique, both have a significant impact on the value that is estimated. Therefore, it’s important to understand the individual factors which influence your One Rep Max and take these into consideration while calculating it.

high angle shot of a woman doing a bench press

Finding Your True One Rep Max

Are you about to attempt a new 1RM? Use the 1RM Warm-up Calculator below or keep reading to determine how much weight you should use to warm up for the best results!

Just enter the weight you plan to attempt below and the 1RM warm-up calculator will show you exactly what weight you should be lifting for your warmup.


More experienced lifters will benefit more from a true one rep max test as theirs is less likely to change as quickly. Here is another proven method from Layne Norton for finding your true one rep max. Rest as much as you need to between sets and if you feel stiff while completing the warmup feel free to add a couple sets in. Just don’t go overboard and tire yourself out.

Warming up to a 1 Rep Max

Warming up can make all the difference in your training. It is especially important when you plan on attempting a 1RM. A good warm-up may lower your chances of injury and increases the likelihood of a successful PR attempt.

It is recommended that before attempting a new 1RM that you first do a general warmup for about five to ten minutes of light physical activity. Light cardio such as the treadmill or mobility drills are recommended to get your blood flowing and prepare your body for lifting.

After the general warm-up use the calculated lifts above or the section below to warm-up for the specific lift you are about to attempt.

How to Calculate Warmup Sets

There are many different ways to calculate warm up sets. Above in the 1RM warm-up calculator is one of the most popular ways. However you don’t need a warm up sets calculator: you can also do the math yourself!

If you are looking for a simple and effective way to calculate warm up sets and reps start with this:

  1. 30% estimated 1RM for 8 reps
  2. 40% for 6 reps
  3. 50% for 4 reps
  4. 60% for 2 reps
  5. 70% for 1 rep
  6. 80% for 1 rep

Testing for Your 1 Rep Max

  1. 90-94% of estimated 1RM for 1
  2. 96-100% of estimated 1RM for 1
  3. 100-104% of estimated 1RM for 1

You can continue to add weight and test from here if you have enough gas left in the tank!

When testing one rep max, it is essential to use a spotter or another similar safety precaution. There is no point in injuring yourself! If you don’t have access to a spotter, using the above calculator is recommended.

In fact, it is recommended that you only test for your true 1RM a few times a year. You can find other alternatives in this article.

How Often Should You Test 1RM

You should only test your max once every 3-4 months at most.

It’s common for lifters to test their strength by attempting a 1RM. And in theory, this is a good practice. Working with near maximal loads increases neural drive, validates your strength program, and just feels good!

However, doing so regularly can be dangerous, especially as you progress in strength. Lifting loads over 90% of your max lift can lead to damaged muscles and tendons, increase your chances of serious injury, and can actually decrease your performance in the gym.

Testing your 1RM too often has far more risks than benefits. These risks include:

Alternatives to Testing Your True Max

Performing a one rep max set isn’t the only way to find your max. Although it is the most accurate, it is also the hardest on your body and will not increase your strength. Therefore, you should only be testing a true one rep max 3 or 4 times a year.

Here are some alternatives that can be performed more frequently without doing as much damage.

Multiple Rep Max Test

One common way to gauge strength on a specific lift is to perform a 2-5 rep max set. This type of test is less dangerous than a 1RM test and can be performed about once a month.

This type of test is precisely what 1RM calculators come in handy for!

RPE-Based Rep Max

An RPE-based rep max is similar to a rep test; however, you aren’t taking yourself to true failure with it. 

For example, you may lift a specified weight for three reps at an 8 RPE (8 out of 10 rate of perceived exertion). If you lift a heavier weight for the same reps at the same RPE, you know you are making progress.

This style of max test is significantly easier on the body, helps increase strength (unlike a true 1RM test), and can be done about once a week.

How to Test My One-Rep Max with the One Rep Max Calculator

Often, trainers and coaches set up programs using your one-rep max as a reference point as they do not know your actual strength level. This allows the trainer to set an effective program without knowing your current strength.

Here are some things to remember when testing your 1RM:

  • The lower your reps, the more accurate your estimate will be
  • Don’t count reps with bad form for the one rep max calculator
  • Remember that each lift has its own 1RM- Don’t use bench to calculate incline bench

What Percentage to Use For Training

Trying to increase speed and power? You should be using 50-60% of your one-rep max and doing 3-5 reps per set for the best results. If you intend to increase your speed, try these workouts!

If your goal is muscle size, use 70-80%. Your rep range should be between 8-12 for maximum results.

Strength oriented goals? Train in the 85-95% range using 3-5 reps per set. New to strength training? Try this workout!

Make sure you get enough calories to increase your size and/or strength. No matter how good your training is, if you don’t eat for results, you won’t get them.

These numbers aren’t the only way to train; they are just some recommendations based on methods that have been shown to give results.

There are other ways to get results. Don’t be afraid to try new methods and mix things up. The one rep max calculator is meant to be a tool, not the answer to your strength concerns.

Not Happy With Your Current One Rep Max?

Here are some tips to help you get those numbers up!

UXO Creatine has been shown to increase your one rep max. For one rep mac calculator

Creatine has been proven to increase one rep max

If you are trying to increase your one rep max, 5 grams a day of creatine should absolutely be part of your supplement regimen.

Train Close to Your One Rep Max

If you’ve already used the one rep max warm-up calculator you should have a pretty good idea of how much you can lift. Now use that to your advantage.

Try training at 80% of your max for four sets of five with long rest between on week one. Then week two increase the percentage of your max you used and continue to do so the following weeks.

Once you can perform this set and rep scheme for 87% of your max, try testing your max again (using the one rep max warm-up calculator of course!).

Perform Walkouts or Holds

Man standing with barbell in back squat position. Walkouts are a great way to increase your squat 1RM

Sometimes you fail a new max attempt simply because you haven’t ever held that weight before. To perform either of these; simply load up the bar with the weight you want to lift (your 1RM or more), unrack it (walk out with it in the case of squats), hold it for a few seconds, and put it back on the rack.

Train Specific Ranges of Motion

If you are getting hung up on a specific portion of a lift, this may be exactly what you need. It looks different depending on where you get hung up but below are some examples based on specific and common issues.

  • Bench Lockout– Use boards or pins to shorten the range of your bench motion to just the top half.
  • Deadlift Lockout– Perform rack pulls, lifting the weight from the mid-thigh position.
  • Coming out of the Hole: Squats– Perform low box squats from below your typical squat depth.

Regardless of what method you use, make sure to work with a spotter any time you training near your one rep max.

Follow a Program

If your main goal is to increase your 1RM we recommend following a strength training program that is built to do just that.

For beginner lifters or those who have never followed a strength training program we recommend Stronglifts or a similar program.

If you are already familiar with strength training but you are needing to push yourself to the next level try one of our other powerlifting programs like Smolov Jr. or browse all of our programs here.

How to Increase Your One Rep Max Quickly and Safely

Improving your 1RM requires hard work and dedication, but it’s also important to keep safety in mind. Start by increasing the weight slowly over time and don’t try to push yourself too far, as this will increase your risk of injury.

Additionally, make sure that you focus on perfecting your form while performing each exercise; this means using a full range of motion and varying the speed at which you lift the weight.

By following these guidelines, you can increase your One Rep Max quickly and safely.

What is the Most Common One Rep Max Calculator Formula?

There are several one rep max calculator formulas. However, the most common is the weight lifted divided by the total of 1.0278 minus the reps performed times 0.0278. This number is then rounded down to the nearest five.

The formula looks like this: ROUND(weight/(1.0278-(0.0278*reps))/5)5

Key Safety Tips for Lifting Heavy Weights

When lifting heavier weights it’s essential to stay safe at all times. Ensuring you perfect your form, use good posture and a full range of motion is important as this will help you work your muscles more effectively and reduce the risk of injury.

Make sure to always warm up sufficiently before attempting your heavier lifts and never try to lift more than what you’re comfortable with. Lastly, be sure to maintain control throughout each movement – accelerating too hard while lifting can easily cause an injury so it’s best to complete each rep slowly and under control. With these tips in mind, you’ll be able to maximize your gains safely!

Did You Find the One Rep Max Calculator Useful?

Let us know in the comments! Don’t have a program for increasing your one rep max? Find a training program here.

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More 1RM info

Is it bad to test your 1 rep max?

There are pros and cons to testing your one rep max. If you are a powerlifter it is a necessary part of the sport. However, you do need to be careful when testing your one rep max.

Doing so overstresses your nervous system and joints, can slow down progress, and carries a high potential for injury. This is why we recommend that you only test when you absolutely need to.

Tools like the one above can help you estimate your 1 rep max so you don’t need to hurt yourself testing it.