The measurement of refractive index and optical activity of organic liquids is of great importance in chemistry. These measurements provide invaluable information regarding the molecular structure, purity of organic compounds and the composition of binary mixtures. Early year there are so many formulae found out by the various scientists. Amongst Lorenz and Lorentz formula is very familiar for the calculation of specific refraction of the organic compounds. It is worthwhile to suggest one more empirical formula for the calculation of specific refraction of organic compounds. This formula is known as Patel Desai Joshi (PDJ)’s formula.