In power powertrain, DC-DC converters, the selection of suitable magnetic core materials is a critical design consideration. It ensures weight and volume reduction and performance enhancement of such types of converters. This study provides a comprehensive comparison of magnetic core materials and a simplified cobweb chart that aids in the initial selection of magnetic core materials for powertrain DC-DC converters. The weighted property method (WPM) is used to systematically select and rank the suitability of the magnetic core materials, and a multi-attribute decision-making analytical hierarchy processes is used to calculate the relative weight of different properties. Based on the peculiar requirements of powertrain DC-DC converters, the most suitable magnetic core materials are identified and ranked with the help of the cobweb chart and the WPM. This study aims at providing a quick reference for designers to ease the selection of suitable magnetic core material for powertrain DC-DC converters.