Refrigerants, especially the halocarbon compounds R-11, R-113 and R-114, are the most suitable organic working fluids for the majority of operational Rankine-cycle engines utilising low grade heat sources. Thus, the quick and accurate evaluation of the thermodynamic and thermo-physical properties of these refrigerants is desirable for the analytical prediction of the performances of individual components of such a Rankine-cycle engine, as well as its overall performance. Computer subroutines have therefore been developed for calculating the properties of refrigerants R-11, R-12, R-13, R-14, R-21, R-22, R-23, R-113, R-114, R-115, R-500, R-502 and R-C318 as functions of their characteristic parameters at a state point. The derived equations and correlations are collated and presented in this paper. The developed sub-routines were used to evaluate the properties of the halocarbons R-11, R-113 and R-114. The generated pressure-enthalpy diagrams are given. The computed properties of R-113, as a representative candidate, are shown in comparison with the other pertinent published data. The results indicate that there is a good agreement between the predicted values, using the programmed correlations and equations evolved in this investigation, and the most authoritative, but sometimes esoteric, data available.