In this study, we calculate the dissociation time/rate from CF-SMD simulations using kinetic models based on the Kramers theory. We investigate a NaCl system and protein-ligand systems: FK506 binding protein with an organic molecule and streptavidin with biotin. We first study the NaCl system as a simple example, showing how the CF-SMD simulation enables the calculation of dissociation time via Bell's and DHS models. Moreover, we compare the results of the CF-SMD simulations to those of an equilibrium MD simulation to verify the rate calculation.