1rm Calculator

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1RM 0
  • Brzycki
  • Baechle
  • Epley
  • Lander
  • Lombardi
  • Mayhew et al.
  • O'conner et al.
  • Wathan

How to use our rep calculator?

To use our squat calculator, enter your weight in the input box. You can enter your weight in kilograms or pounds. Select the number of reps from 1 to 20. You may opt-out for any other 1rm equation than the Brzycki's (default), by using the advanced options button. Other equations include Baechle, Epley, Lander, Lombardi, Mayhew et al, O'Conner et al, and Wathan. Click the "Calculate" button, and the max rep calculator will calculate your 1rm in a moment. It will calculate the 1rm for you using all of the methods and equations available in the advanced options and show them in result pan.

What is One Rep Max?

1RM stands for one rep maximum. The overall weight that can be lifted in an attempt is one rep max. To measure the real strength, it could be the best way out there. The most precise method to check the one rep max is to use a barbell for testing.

Nonetheless, this can affect the plan, recovery time, and theoretically increase the likelihood of injury. Different methods are used to calculate 1RM. Brzycki, Epley, and Landers established formulas that are very reliable and common. More experienced lifters may need to check NSCA (National Strength and Conditioning Association) figures for exercise.

Why is 1RM important?

Many plans recommend a certain percentage of your 1RM while training. You need to know your 1RM to follow the program. Sometimes, when you don't carry out one rep lift, you may want to monitor progress and train with periodic schemes where you can compare work done on different sets. You can calculate without testing how much more reps should be used when conditioning. The main purpose to find your 1RM is to compare it to your 1RM, which is tested before. If you measure 1RM and check 1RM is much smaller, it is a good sign that you either have a lagging muscle or wrong lifting technique that stops you from achieving true 1RM. Nevertheless, it should be remembered that technically difficult Olympic activities are not going well with these measurements due to huge technological variability. This variability could be a limiting factor.

How to calculate one rep max?

You may assume that your 1RM limit doesn't matter because you won't practice the heavy lifts anyway. One day, however, you may see a program demanding 65 percent of your 1RM to be used on a lift.

In this scenario, you either have to check or measure the 1RM. Testing the 1RM can be very painful, and a high degree of vigilance is needed to prevent injuries.

The good news is that you can calculate your 1RM without taking a test. Exercise researchers created a method that is pretty precise to calculate for most people, and this calculator is based on the same formula.

1rm formula

You can estimate your 1RM with various formulas. These formulas are slightly different in calculations. The Brzycki formula from Matt Brzycki is the most popular and tested for accuracy.

1rm = weight / ( 1.0278 – 0.0278 × reps )

One Rep Max calculation Example

If you could lift 80 kg for 5 repetitions, the 1RM would be calculated as:

1rm = \(\dfrac{80}{( 1.0278 - 0.0278 \times 5 )} = 90 kg\)

If your program is like this, you can continue to lift your five reps while still gaining an idea of your strength.

1RM estimation will be more unreliable if you are further away from one rep. Say that you can lift 10 kg to 30 reps, your 1RM would be 52 kg with Brzycki's formula. Nonetheless, the trust of this number is so poor that the estimate is not worthwhile.

As a guideline, don't think about anything more than 10 reps. You may know that you usually get 5 kg of the real 1RM, or more or less for the planning purposes.

You can measure the 1RM for more than a single way. These are the different formulas to calculate your 1RM:

Brzycki Formula

1rm = \(\text{weight} \times \Big(\dfrac{36 }{(37 - \text{reps})}\Big)\)

Epley Formula

1rm = \(\text{weight} \times (1 + 0.0333 × \text{reps})\)

Lander Formula

1rm = \(\dfrac{(100 \times \text{weight})}{(101.3 - 2.67123 \times \text{reps})}\)

Lombardi Formula

1rm = \(\text{weight} \times \text{reps}\)

Mayhew et al. Formula

1rm = \(\dfrac{(100 \times \text{weight})}{(52.2 + (41.9 \times e^{-0.055} \times \text{reps}))}\)

O’Conner et al. Formula

1rm = \(\text{weight} \times (1 + 0.025 \times \text{reps})\)

Wathan Formula

1rm = \(\dfrac{(100 \times \text{weight})}{(48.8 + (53.8 \times e^{-0.075} \times reps))}\)

1 Rep Max Chart

One Rep Max chart  different formulas This comparison

By WheyProteinIsolate - Own work, CC BY-SA 4.0, Link

1RM Calculation with an example

Let's assume you can raise 220 pounds on the bent-over row for ten reps, with good form. This helps us not only to measure the one-rep max, but also other loads, which includes your 70% 1RM, 55% 1RM, or 85% 1RM, depending on the requirements of your program.

The formula calculates the 1rm using the total weight you can raise during a move given to you and the number of reps that you can do before tiredness or slowing down. Let's make sure you can make 220 pounds for 10 reps for the chain. Put these values in the above calculator, and you will see the estimated 1rm.

Working out with your 1rm

Training coaches build programs based on your 1RM percentage because they don't know the exact level of your strength. They know the percentage they want to use with respect to your one-rep max.

Some of the training plans are planned in other ways and instruct you to build the 3RM, 6RM, etc. What is special here is that you will be asked to do 3RM instead of performing a percentage of your one-rep max. This indicates that only three participants use one weight. You will need the table given in the end to effectively make a different conversion.

Assume that your training or work out instructor needs you to do front squats with 3RM and 5RM. Assume that you know that you can do 245 pounds with 8 rep sets. If you can perform eight repetitions perfectly, you will be amazed to know that eight means 80% of your 1RM. Check the table given in the end of the post.

Start measurement 1RM by dividing your 1RM by 0.80. This yields an average of 306.25 and is rounded to 305. If 3RM corresponds to 93% 1RM, multiply 305 with 0.93, estimating that your working weight is 285 pounds in rounded figures. Your 5RM is 305 × 0.87, which gives you approximately 265 pounds of working weight.

Testing 1RM

Apart from estimates, if you want to check your true 1rm, there is no other way except lifting the weight with full passion and hard work. It is the only way to test the true 1rm if you are not satisfied with the estimated value.

It stresses the body more than regular training, so it will take longer to recover. Ensure that safety, such as sawhorses, spotters, or security pins are in place. Particularly for bench presses where the squat or overhead press is not easy to bail.

Don't go directly to your 1RM test, but gradually build to it. It warms you up and helps to brace your body for weight. Don't think about burning on the way; you can actually lift more. Only rest between lifts when it gets heavy.

You should know the rules of the test. You cannot avoid parallel in a squat, hit the chest on a bench press, or lower the bar on deadlifting if you want to calculate the True 1RM.

Exercises to test true 1rm

The following exercises are used to test true 1rm.

Bench Press

It is an exercise for the training of weight lifting in which the trainee press the weight towards upside in lying position on a bench or table. The workout uses deltoids, triceps, and pectoralis major, among other muscle stabilizers. A pair of dumbbells can also be used to hold the weight but in general, a barbell is used.


A squat is a strength workout in which the trainee lowers his / her hips when standing and then comes back up. The hip and the knee bend during the descend of a squat. The hip and knee joints move in turn, and the ankle joints expand as the trainee rises upward.


The deadlift is also an exercise for the training of weight lifting where a heavy barbell is raised from the ground to a hip level before putting back on the ground, perpendicular to the floor. This is one of three exercises for powerlifting together with bench press and squats.

Shoulder press

The shoulder press is a weight exercise, usually done while standing, with many variations. The weight from the rack position is straight up pressed until the arms are locked overhead, while the abs, lower back, and legs are balanced.

1 REP-MAX Percentages Table

The following 1 rep max chart represents the percentage of 1rm against the number of reps.

Repetitions Percentage of 1RM
1 100%
2 97%
3 94 %
4 92%
5 89%
6 86%
7 83%
8 81%
9 78%
10 75%
11 73%
12 71%
13 70%
14 68%
15 67%
16 65%
17 64%
18 63%
19 61%
20 60%
21 59%
22 58%
23 57%
24 56%
25 55%
26 54%
27 53%
28 52%
29 51%
30 50%
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