Nowadays, power electronics systems developed need small size, reliable, high quality and efficient switch mode power supplies. However, switch mode power supplies also require determining the operating parameters accurately for achieving intended energy conversion effectively and faultlessly. In this study, an interactive and object oriented parameter determination system was designed for Buck, Boost, Buck-Boost and Cuk converter topologies. Users have used the system interface easily through the interactivity of the system and the user requests have been accomplished quickly through the object oriented programming. Accuracy and reliability of the system have been tested separately for each type of the converter and it has been shown that the performance in the process of determining the parameters of the system is effective and optimum. © 2011 IEEE.