On-chip conductors such as clock and power distribution networks require accurately modeling of the skin effect. Furthermore, to incorporate the skin effect in the existing generic simulation tools such as SPICE, simple frequency independent lumped-element circuit models are needed. A rule-based R-L circuit model is proposed in this paper that predicts the skin effect in the entire frequency range accurately. This circuit model only contains a few parallel branches of resistors and inductors. A maximum error in impedance values of less than 3% is achieved using only two or three constant element branches.