This paper deals with an efficient method for calculation of normalized cutoff frequency and propagation parameters of a class of waveguides. The developed decoupled region hybrid method (DRHM) is based on suitable separation of sub regions and of subsequent application of one or more conformal mapping and using the finite element method. In this case single or multiple mapping in each sub region enables the use of rectangular mesh in the final stage. The organization of data files and computer programmes are modular and easily applicable to various fiber configurations. Illustrative calculations are made for step-index coupled core fibers.