Linear rolling guides are used for realizing a translational motion of mechanical elements or assemblies e.g. in industrial robots, handling or CNC machines. Their reliability is highly desirable to meet the requirements of Industry 4.0, and hence the accurate load identification of linear guides is needed. The objective of this article is to identify a dynamical load of linear guides based on the substitutive mathematical model of machines. Where, the kinematic excitation, mass, inertia parameters of moving bodies and elastic and damping behaviour of linear guides are defined. The simulation of specific operating conditions is reached by Lagrange equations in a vector form. This way conveniently enables respecting the effect of nonconservative forces in the calculation. The article comprehensively describes the method of the dynamical load calculation of linear rolling guides, which is usable for a wide range of machines, their design as well as the design of linear guides.