The Wathen Max Weight calculator computes the approximate maximum weight one can lift using the Wathen formula.
INSTRUCTIONS: Choose your preferred units and enter the following:
Max Weight (1RM): The calculator returns the approximate max weight in pounds. However, this can be automatically converted to other mass or weight units (e.g. kilograms) via the pull-down menu.
Max Repetition Weight formulas like Wathen are intended to provide an estimate on the maximum weight one can lift without having to attempt such a lift. The motivation is to avoid injuries associated with lifting one's max. The Wathen One Max Weight formula is:
1RM = (100*w) / (48.8 + (53.8*(E**((-1)*0.075*r))) )