An approach to a simplified calculation of the characteristics of a steady gas flow through a pipeline is proposed. In this approach, the pressure is calculated using an isothermal model; the temperature analysis is reduced to a cubic equation solving. A simple analytical gas leak point coordinate dependence on the pressure and gas flow values is obtained at outlet from the pipeline. The result of comparison of calculations for the general and simplified models of gas flow in pipelines is presented. A criterion has been determined for the fulfillment of which it is permissible to use a simplified approach to calculating the gas characteristics and the leak point coordinates. Using an example of practical interest, the high accuracy of the calculation according to the proposed approach of both pressure and temperature in the flow and the gas leak coordinate in the pipeline is demonstrated.