The magnetically induced current-density susceptibility also called current density has been calculated for a recently synthesized octaethyl porphyrin (OEP) zinc(II) dication with formally 16 pi electrons. Numerical integration of the current density passing selected chemical bonds yields the current pathway around the porphyrinoid ring and the strength of the ring current. The current strengths show that the OEP-Zn(II) dication is strongly antiaromatic as also concluded experimentally. The calculation of the ring-current pathway shows that all 24 pi electrons participate in the transport of the ring current, since the current splits into inner and outer branches of practically equal strengths at the four pyrrolic rings. The corresponding neutral octaethyl porphyrinoid without Zn and inner hydrogens is found to be antiaromatic sustaining a paratropic ring current along the inner pathway with 16 pi electrons. The neutral OEP-Zn(II) molecule with formally 18 pi electrons is found to be almost as aromatic as free-base porphyrin. However, also in this case all 26 pi electrons contribute to the ring current as for free-base porphyrin. A comparison of calculated and measured 1H NMR chemical shifts is presented. The current strength susceptibility under experimental conditions has been estimated by assuming a linear relation between experimental shielding constants and calculated current strengths.