An effective spacing is calculated for each physical spacing between two or more neighbor nets of a target net. Segment boundaries are determined based on the calculated effective spacing to define segments for the target net and one of the segments is selected. A metal configuration for the selected segment is identified and a table of capacitance per-unit-length is accessed for the identified metal configuration to return an above capacitance value, a below capacitance value, a left-side capacitance value, and a right-side capacitance value for the corresponding segment, the table comprising at least a two-dimensional (2D) table. The capacitance values are scaled based on a corresponding segment length determined from the calculated effective spacing. The selecting, identifying, accessing and scaling operations are repeated for each remaining segment of the target net. Optionally, the above, below, left, and right capacitance values for all segments of the target net are summed.