Engineering Dimensions, Units, and Conversions delves into the analysis and application of the dimensions, units, and unit conversions in engineering practical use. It demonstrates the importance of dimensional homogeneity and unit consistency. Offering a comprehensive exploration of both primary and secondary units, the book presents detailed portrayals of various unit systems in both the English system and the International System (SI). It provides insight into conversion ratios and introduces software-based methodologies. The book also examines dimensioning in drawings, including dimensioning basics and numerous exercises of object and system dimensioning. The book will be a valuable reference for practicing engineers and researchers engaged in engineering research and development. It will also be of interest to undergraduate and graduate students in engineering disciplines.