In this study, we focus on the exo-chair and exo-boat isomers of JP-10 using density functional theory (DFT) calculations. By analysing their structural and electronic differences, we aim to provide insight into how these isomers influence JP-10's properties and their performance as an HED fuel. Moreover, we will compute the 13 C-NMR and 1 H-NMR chemical shifts of these isomers and compare them with available experimental data , to validate our theoretical approach. The calculated NMR chemical shifts will highlight sitespecific variations in the chemical environments of carbon and hydrogen atoms as the molecule transitions between chair and boat conformations. This will enable the complete and unambiguous assignment of NMR chemical shifts for both isomers. Understanding these molecular-level details is critical not only for optimizing JP-10's performance but also for informing the design of next-generation HED fuels and SAF blends.