This paper describes a resistance calculation program for a layout verification system called EMAP. A new resistance calculation algorithm, based on the finite-element method, and a generalized resistor model, used in this program, are discussed. Contact resistance effects, pinch resistors, and other kinds of resistance appearing in LSI's are considered in the proposed model. The proposed two-dimensional model, in which an inherent three-dimensional structure of resistors is embedded, allows efficient and accurate resistance calculation. The resistance value for an arbitrarily shaped multiregional resistivity and multiport resistor can be calculated efficiently by the proposed algorithm. The algorithm, called direct admittance matrix derivation, makes it possible to eliminate the tedious boundary condition treatment, and provides efficient matrix manipulation. Implementation techniques and related algorithms are discussed; these include resistor recognition from mask artwork, mesh generation for finite elements, node numbering for matrix bandwidth reduction, some properties of matrices appearing in the proposed algorithm, and a circuit representation method for the derived matrices. Some implementation results are also discussed.