An apparatus for extracting capacitances of arbitrarily oriented three-dimensional interconnects includes a processor configured to recursively execute a floating random walk algorithm over a plurality of points for a plurality of conductors, to permit determination of a potential at a plurality of points on a Gaussian surface around each conductor and determination of a coupling capacitance between each conductor. Each iteration includes selecting an initial domain centered about an initial boundary point on a Gaussian surface of an initial conductor, determining a new boundary point on the initial domain from which a successive domain centered about the new boundary point may be selected, and determining a corresponding successive boundary point on the successive domain, each iteration continuing until the new boundary point or the corresponding successive boundary point terminates on a boundary having a known potential. Each selected domain may be rotated to align with the nearest conductor.