The Epley 1 Rep Max Formula calculator computes the one repetition max using the Epley formula, the weight lifted and the number of repetitions.
INSTRUCTIONS: Choose weight units and enter the following:
One Rep Max (1RM): The calculator returns the One Repetition Maximum in pounds. However, this can be automatically converted to other weight units (e.g. kilograms) via the pull-down menu.
Theis as follows:
The formula estimates how much the weight lifter could have lifted one time (RM) based on the maximum number of reps (r) of a lesser weight (w). This method is used in some competitions and in many gyms to avoid injuries and to provide a more consistent measure of endurance and strength.