[en] Described is the analytical method for calculation of hydraulic resistance and real steam quality in a heated channel, subcooled water boiling at the temperature below the saturation temperature. While developing the method, only one empiric parameter, obtained earlier on the basis of numerous experimental data processing, was used. Formulas, suitable for engineering calculations of heat exchanger channels with surface boiling, were obtained on the basis of the above method. Comparison of the calculation results with the experimental data shows that the method is useful for the calculations of the above characteristics for various-configuration channels at low and medium pressures. The only limitation of the method application is the ambiguity of the channel hydraulic characteristic