Machinetools belong to the basic technological equipment in mechanical engineering ensuring the creation of other machines with high accuracy and productivity unattainable in coming decades on the basis of additive techniques. Machining accuracy on machinetools is an integral index of quality and despite the diversity of approaches to the identification of correla-tions, computations and estimates of machining accuracy, the value of a general error seems to be as a sum of partial errors. A significant part in the formation of a general error of machining cause machinetools them-selves. Besides, a significant role in assurance of guaranties for machinetools users (operators) the standards for their geometrical accuracy play. A significant problem having scientific and practical meaning is the absence of a single approach substantiated scientifically to the formation of a system of such standards both for machine-tools of new types, and for the revision of the system with actual standards on geometrical accuracy of machinetools. In the paper there are offered methodological fundamentals for the parameters standardization of machine-tools geometrical accuracy on the basis of revealed interrelations between accuracy of units and parts surfaces machined at the use of a variational method for the computation of machines accuracy. The practical use of the approach offered requires both the development of the variational method itself for the computation of machines accuracy in the field of obtaining corresponding estimates of accuracy of various surfaces machined, for example, deviations from parallelism of two faces and others, and thorough investigations of the structure of relationship equations themselves.