Torque can be calculated by taking the cross product of two variables. The formula is τ = rF sin θ. The moment arm is denoted as "r" and defined as the distance from the pivoting point to where the force is acting. The force acting on the moment arm is denoted as "F."

To find the cross product of these two variable, "r" and "F" are multiplied by each other and then by the sine of the angle between the moment arm and the force, denoted as theta (θ).

In general, the longer the moment arm, the less force is needed to move the arm. Conversely, the closer the force is to the pivot, the more force is needed to move the arm.