Engineering formula
Moment of a Force About a Point
$$M = Fd$$
The magnitude of the moment of a force about a point equals the force magnitude multiplied by the moment arm, the shortest distance from the point to the force's line of action:
$$M_O = Fd$$
where $M_O$ is the moment about point $O$, $F$ is the force magnitude, and $d$ is the moment arm. In a planar problem, the sign represents the sense of rotation: counterclockwise is commonly taken as positive and clockwise as negative.