In physics, net force is the overall force acting on an object. In order to calculate the net force, the body is isolated and interactions with the environment or oigg constraints are represented as forces and torques in a free-body diagram.

The net force does not have the same effect on the movement of the object as the original system forces, unless the point of application of the net force and an associated torque are determined so that they form the resultant force and torque. It is always possible to determine the torque associated with a point of application of a net force so that it maintains the movement of the object under the original system of forces.