The reference electrode plays an important role in the determination of the electrocatalytic activity of a given electrode material. The hydrogen reference electrode has several advantages, as it is stable, can be used in the whole range of pH values, and does not contaminate the system. However, its use is not widespread due to certain difficulties related to its construction and operation. In this context, we report the design of a reversible hydrogen electrode (RHE) characterized by its simplicity, reproducibility, portability, stability, and precision. Moreover, rigorous equations for the variation of the RHE potential on the solution concentration, temperature, and pressure were derived as well as for the conversion of a working electrode potential referred to RHE to the standard hydrogen electrode (SHE).