TheHarkins-Jordan correction factors which make the ring method an accurate and absolute method of measuring surface and interfacial tensions, are calcuated theoretically and made available in a tabulated form. The applicable range of the numerical tabulation far exceeds the range of those available in the literature which have been obtained experimentally. With the tabulation, the ring method may be used to measure the interfacial tensions of liquid systems in which the density difference across the interface is very small and the interfacial tension is large, or in which the density difference is large and the tension is small. The theoretical calculations also provide information on the state of the ring at the liquid interface which may be used to increase accuracy of the ring method.