The output of this calculator is the pressure drop per unit length given per bar/km. This digital output must be multiplied by the equivalent length of the total pressure drop across the length of the tube to calculate the length of the tube. The total equivalent length of the tube obtained by the length of the straight tube of the equivalent length of all the tubes.

The pressure drop per unit length of the pipe based on the Lockhart-Martinelli Method is calculated for the calculator given below. Various methods for predicting a two-phase flow system can be used.