A recently developed renormalization group theory for fluids can be used to calculate nonuniversal as well as universal critical point properties and also to predict the changes in pressure and other thermal properties that occur out to substantial distances away from the critical point. These features of the theory are illustrated here for a model square-well gas. The calculated pressure, temperature, and density at the critical point and transition to noncritical behavior away from the critical point for this gas are compared with measured properties of parahydrogen reported in the literature.