The signals of protons, which have other magnetically inequivalent protons at geminal or vicinal positions are split because of spin-spin coupling between these neighboring protons. The splitting of the signal can be measured by calculating the coupling constant of the concerned signal. Coupling constant is a constant value, independent of the magnetic field strength and it mostly depends upon the extent of interaction between two proton systems. Denoted by “J”, the values of coupling constants are calculated in Hz.