Power flow studies are of fundamental importance in the planning and operation of an electric power system. They consist in obtaining values of active and reactive power in lines and transformers, magnitude and angle values of the voltage in each bus, and some other quantities of interest, which allow checks on the network status. These studies are performed using computer programs that are based on calculation methods such as Gauss, Gauss-Seidel, Newton-Raphson, Newton-Raphson with constant Jacobian, decoupled methods and the Linear Active Power Flow method (DC Model). This project emphasizes the Linear Active Power Flow method (DC Model). An important property of this linearized model is that it always provides a solution, even for problems that cannot be solved by conventional methods for calculating the load flow. The purpose of this work was to develop a computer program based on the dc model for calculating the linear active power flow considering the losses. The results obtained were compared with those ones of a conventional power flow program.