The prediction of shrinkage and warpage of crystalline polymers is quite difficult. This is because of the complications of the crystallization process and associated material property changes. Particularly, the pVT behavior is dependent on the cooling rate during injection molding. Traditionally, the pVT data were measured in a device where the cooling rate is very slow compared to that in the aortal injection molding process. This cooling-rate dependent pVT data is considered to affect the shrinkage and warpage calculation significantly. In the present study, a method has been developed to obtain pVT behavior at the same cooling rate as in the actual injection molding process. Obtaining other material data such as viscosity, thermal conductivity and heat capacity at the cooling rate of the actual injection molding process has also been considered. Injection-molding experiments have been conducted to measure the shrinkage of a part using semi-crystalline polymers. The polymers used in this study are polyamide 66 (PA 66) and polybutylene terephthalate (PBT). Simulation has been done to calculate the shrinkage using the cooling-rate dependent material properties. Using the fast-cool pVT behavior; the agreement between the simulation and the experiment improved significantly compared to the traditional approach.