This article presents a computational tool to calculate some parameters of hydroelectric plants, focusing mainly on microhydroelectric generation; it also evaluates the energy potential of small hydro plants. This computational tool was developed using MATLAB, and it presents a graphical interface that makes it user friendly. The computer program and related knowledge are easy to understand and apply; because the equations implemented are very simple, the tool is not computationally demanding. In fact, although it was developed and designed to help teach undergraduate electrical engineering students attending on classes hydroelectric generation, this tool can be used to estimate the hydroelectric generation potential of a site, which is the first step before starting a hydro plant project.