@User The resistivity of the metal layers would be necessary, or at least the material so we could look it up. Ohms per square would probably be fine. We need the resistance per via between the metal layers too, for each type of via used. There are a lot of vias in many inductors. Also the dielectric constant of all insulating layers (below, between and above the metal layers), and their thickness. For accurate Q prediction the resitivity and thickness of all silicon layers in the substrate below the inductor is helpful too, to allow FastHenry to calculate the eddy currents induced in it, and perhaps to help predict the resistance in series with the parasitic capacitance to substrate (though a slotted metal shield mostly gets rid of that).