One Rep Max Calculator: Calculate Your 1RM for Fitness and Strength Training

One Rep Max Calculator

Calculate your one rep maximum (1rm) for fitness and strength training.

The one rep max calculator below will help you estimate the maximum poundage you can complete without necessarily having to do a single rep max lift. Simply enter the number of reps you can complete with the weight used into the estimator. Once this information is entered, select the formula and hit the calculate button.

Please keep in mind that these are only estimations and may not always be accurate. For example, because squatting utilizes more muscle groups than curling, research has discovered that some athletes can complete more reps of their predicted maximum capacity during a squat.

Additionally, your one rep max might change on a frequent basis, depending on factors like sleep quality and how well you have recuperated from prior sessions. Thus, don't ever be hesitant to reduce  weight for a given exercise.

Weight in:


Some other common formulas for calculating Maximum Load (1RM)

Brzycki’s equation (1993)

1RM = Weight ÷ (1.0278 – (0.0278 × number of repetitions))

Baechle equation (2000)

1RM = Weight × (1 + (0.033 × number of repetition))

Lander’s formula

1RM = (100 × Weight) ÷ (101.3 – 2.67123 × number of repetitions)

O’Conner’s formula

1RM = weight × (1 + 0.025 × number of repetitions)

Mayhew et. al formula

1RM = (100 × Weight) ÷ (52.2 + (41.9 × e-0.055 × number of repetitions))

Wathan’s formula

1RM = (100 × Weight) ÷ (48.8 + (53.8 × e-0.075 × number of repetitions))

Max Bench Press Calculation

Here is how to run the bench press test. It requires a spotter, bench, barbell, and weights.

1. Athlete warms up for about 10 minutes.

2. The spotter counts the number of bench presses that are done successfully.

3. Next, the athlete bench presses until they are unable to do anymore.

4. The spotter counts the number of benches that are done successfully.

5. If the number of bench presses exceeds 8, the athlete is allowed to rest for ten minutes while the weight is increased. The test is repeated.

6. Using the maximum load calculator, the instructor can then calculate the 1 rep max of the athlete.

Looking for further charts, formulas, or equations on the single rep max? Click the link below.
One Rep Max Chart

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