1RM Calculator

About the Brzycki Formula:

The formula used to estimate the 1RM is known as the Brzycki Formula:

1RM=weight1.0278−(0.0278×reps)1RM = \frac{\text{weight}}{1.0278 – (0.0278 \times \text{reps})}1RM=1.0278−(0.0278×reps)weight

It is a widely used and validated method for calculating the 1-repetition maximum (1RM) based on the weight lifted and the number of repetitions performed.

Reference: Brzycki, M. (1993). Strength testing: Predicting a one-rep max from reps-to-fatigue. Journal of Physical Education, Recreation & Dance, 64(1), 88-90.