Starting from the original definition of the solubility parameter, two models are developed to calculate the solubility parameter utilizing Perturbed-Chain SAFT and Cubic-Plus-Association equations of state, respectively. C3 similar to C12 n-alkanes and C1 similar to C5 1-alcohols, which represent the nonassociative and associative compounds, respectively, were investigated mainly over wide ranges of temperature and pressure. Solubility parameters calculated by two models are in good agreement with Hansen solubility parameters (HSP) and the results of Monte Carlo simulation for all of these selected molecule. It is also found that the solubility parameter increases monotonically with increasing pressure, and decreases with increasing temperature for all of these studied molecules.