Disclosed are embodiments for modeling the total resistance (Rtot) of a contact bar. In the embodiments, sections of the contact bar are demarcated depending upon the location of an additional interconnect structure, which is on the contact bar, and relative to a diffusion region, which is traversed and contacted by the contact bar. For each of the sections, section-specific current density boundary conditions are established, section-specific sheet current density expressions are developed, which assume that current flow is continuous in the normal direction relative to each boundary between any two adjacent sections and which satisfy both the section-specific current density boundary conditions and a stable current flow continuity equation, and a section-specific resistance expression is developed using the section-specific sheet current density expressions. Finally, the total resistance expression for the contact bar is developed by adding the section-specific resistance expressions for all of the sections.