The work objective is to develop methods for defining the friction coefficient of fractal surfaces.
 The problem to which the paper is devoted: estimation of the friction coefficient.
 Research methods: modelling of contact interaction, analytical calculations.
 The novelty of the work: the friction coefficient of fractal surfaces is estimated based on the estimation of the force interaction of microirregularities.
 Results of the study: the procedure for defining the components of the friction coefficient depending on the parameters of fractal roughness is presented; quantitative results of the friction coefficient of fractal surfaces are obtained. 
 Conclusions: the fractal contact model is implemented at low contact pressure, and with the growth of the fractal dimension, the friction coefficient decreases.