This research establishes an extensive set of algorithms for the precise evaluation of fuel consumption across a range of engine types and systems onboard LNG carriers (LNGCs). The principal objective of this research is the development of a modern, universally applicable, and refined methodology tailored to LNGCs. This methodology encompasses the comprehensive calculation of both fuel consumption and atmospheric emissions, accommodating the variability in engine configurations. Furthermore, the integration of empirical data derived from 73 operational LNGCs yields a meticulously crafted operational profile. This consequential outcome of our study carries significant implications for addressing forthcoming modeling complexities specific to LNGCs.