It is important to know solar energy potential before setting up any solar energy system. It is usually simulated, as the measurement is not easily attainable in every place. For this purpose, a computer program has been developed to determine solar radiation. The program, which is developed using Delphi language and can run under Windows operating systems, uses altitude, latitude, date, and temperature of the place as an input and both daily and monthly solar radiation containing direct, diffuse, and global can be obtained from output. Moreover, it provides solar radiation data to compute for horizontal and tilted surfaces.