In this paper, we present the closed-form models of conductor thickness dependent dispersive line parameters and losses, of Asymmetric Coplanar Striplines (ACPS) on isotropic dielectric substrates. The dispersive empirical expressions for the ACPS from literature are improved to include the finite conductivity and finite conductor thickness in propagation characteristics and losses. All developed models are verified against the results obtained using the experiments, MoM based LINPAR and EM-simulators for frequency range 0.1 GHz–60 GHz over wide range of parameters. The average deviation of the model is within 2.5%.