Different methods have been developed for determining the performances of thermoelectric (TE) modules. One of them is a method, developed by Ahiska et al., based on certain parameters measured easily such as temperature, current and voltage. According to this method, in order to determine the performance of a thermal and electrical of TE module, firstly it is necessary to determine the parameters I-max, V-max and E-max. For this purpose, a large number of measurements are used in the determination of the parameters of TE module conventionally. Therefore, this procedure requires extensive time to obtain the expected thermal stability. In this study, a new algorithm is developed based on parabola calculations in order to determine the parameters Imax, Vmax and Emax of TE modules and systems by less measurement in shorter time. The new parabolic algorithm was adapted to thermoelectric performance analysis system (TEPAS) that was developed previously. In order to determine the performance of the test system based on the new parabolic algorithm, experimental studies were made using Melcor CP1.4-127-10 model. Relative error rates of obtained parameters using new parabola algorithm with respect to classical method are Delta T-max to 0.3%, I-max to 1%, V-max to 0.8% and E-max to 2.9%. As a result; it is understood that the parameters I-max, V-max and E-max of TE module can be obtained correctly and in a shorter time using this new method based on parabola algorithm.