We have modeled the current-induced magnetic field that arise in a single-molecule junction under low bias by invoking the Biot-Savart law. Within the combined DFT-NEGF formalism we thus map the ballistic current density and magnetic field of several cyclic and linearly conjugated organic molecules where strong helical or ring currents appear. Based on the Biot-Savart law and the right-hand rule, we assume that the following three requirements must be fulfilled to achieve substantial enhancement of the magnetic field: