Partial inductances are computed herein for the via transitions between parallel planes. A hybrid method proposed for the inductance calculation correlates the definition of the partial inductance and a resonant cavity model. The hybrid method is corroborated by comparison with the partial-element equivalent-circuit and the cavity methods, as well as measurements. The portions of the plane net and via net inductances are quantified, and the contribution of each plane current to the plane net inductance is quantitatively analyzed. © 2011 IEEE.