An equivalent circuit approach was presented in this paper to evaluate low-frequency magnetic fields in the presence of non-ferromagnetic plates. Thin plates and conductors, as well as others, were modeled as interconnected and coupled circuit components. The eddy currents on the plates were then solved with a circuit analysis technique. The resultant magnetic field was calculated with the Biot-Savart law. The proposed approach was tested on two plate models, and the results were compared with those obtained from the boundary-element method and the laboratory experiment. A good agreement among these results was found. The proposed method is effective in handling multi-plate problems at low frequency.