<p>The method of calculating the roughness of gear teeth depending on the parameters of gear meshing of gears at rolling friction with slippage. A model for calculating the equilibrium <br /> roughness of the surface in the form of a truncated cone, made on the basis of a spherical roughness model. Methods of determining the technological roughness protrusion; calculation of the depth of implementation of the protrusion of equilibrium roughness in the surface of the counter body; assessment of the pattern of change in the roughness of the gear teeth depending on the meshing module, load in the meshing. A method of evaluating the change in the ratio of the actual and nominal contact area depending on the degree of relative slip between the teeth of the gears, changes in the actual contact area of the gear teeth depending on the meshing module of the gear.</p>