The aim of this paper is the prediction of solid solubilities in supercritical fluids (SCF) on an order-of-magnitude basis. A further aim is to clarify some of the computational aspects of the Boublik and Mansoori equations for the perturbed hard-sphere used in the estimation of solubility. Modelling the solubilities of heavy hydrocarbons and other organics provides an average value for the pair-potential integral function a(12). The latter varies by only +/- 30% from one solute to the other over relatively wide ranges of pressure (P) and temperature (T). Thus, it is possible to use a mean value to estimate approximate solubilities in SCF, which are useful in some stages of engineering work where order-of-magnitude data is sufficient. On the other hand, the (one-parameter) Peng-Robinson equation of state with the interaction parameter optimized for each solute gives no clear guidance.