The paper continues a series of articles devoted to the procedure proposed by the authors how to calculate the required elements’ parameters and the output optical power level of the fiber-optic interferometric schemes with time-division multiplexing (TDM) of sensing elements. In particular, the schemes based on fiber Bragg gratings have been analyzed. The proposed method enables to ensure uniformity of powers of optical signals from individual sensing elements, as well as to evaluate how the deviations of elements’ parameters from the nominal ones influence the optical powers. According to the calculation methodology, a sequence of applying the required expressions was substantiated and some obtained results and an analysis of characteristic behaviors for the considered optical fiber circuits were exemplified. The proposed approach was recommended for design of interferometric optical fiber sensors with multiplexed sensing elements.