Hittorf's method is a moving boundary method used to determine the transport numbers of ions in an electrolyte solution. Kohlrausch's law of independent migration of ions states that the equivalent conductance of an electrolyte at infinite dilution is equal to the sum of the equivalent conductances of the individual ions that make up the electrolyte. A formula is provided to calculate the transport numbers of ions based on the distance traveled by the boundary, concentration of the electrolyte solution, and total number of ions.