A method for calculating pressure losses during pneumatic transport is considered with the aim of choosing the most favorable operating mode, which allows to reduce the consumption of compressed air. It has been established that the generally accepted formulas for calculating pressure losses along the path, calculated as the sum of the pressure losses for pure gas and material, do not explain the fact of the initial decrease in pressure losses with increasing air flow rate, and then their growth. The importance of accounting for changes in air density and air flow velocity along the length of the pipe, as well as the need to take into account the overlap of part of the pipeline section with material in the case of high concentrations, is shown. It is proposed to determine the pressure loss using the Bernoulli equation in integral form, for example, the Gauss method using eight nodes. The applicability of the method for calculating both straight and inclined sections of pipelines is established. The experimental results of studying and analyzing the proposed isothermal model in a vacuum pneumatic transport laboratory installation are presented. An example of calculating the pressure loss for an industrial pneumatic conveying system with a pipe length of 450 m and an inner diameter of 147 mm at various flow rates of the material is shown. Ill. 4. Ref. 21. Tab. 1.