Industry standards and practices define a number of mathematical and physical methods to estimate the cargo carrying volume capacity of a vehicle. While some have roots dating back decades, others try to assess the utility of the space for cargo by subjective measurements. Each these methods have their own inherent merits and deficiencies.The purpose of this paper is to highlight the differences in calculated cargo volume amongst the following practices: Society of Automobile Engineers (SAE) J1100International Organization for Standardization (ISO 3832),Global Car manufacturer's Information Exchange group (GCIE),Consumer Reports.This paper provides a method and associated rationale for constructing a new cargo volume calculation practice that attempts to harmonize these procedures into a more contiguous practice. This homologation will benefit publishing industry, vehicle manufacturers and customers alike. The publishing industry would have a common cargo reporting practice to more accurately inform their readers, reducing proliferation of conflicting reports of cargo volumes. Manufacturers could in turn, optimize their products to a single standard rather than sub-optimizing them to many different ones. The customer benefits from a common measuring and reporting system that would readily allow them to more accurately compare the cargo volumes of different manufacturers' vehicles.