I am trying to duplicate an already existing inductor by buying the components and winding it myself. I have found several different sources that give me different equations for determining inductance. My questions are as follow: - What is the governing equation for determining the inductance of a cylinder with wire wound around it. - What affect does layering the wire have. ie wind it once, go back and re-wind over it a second time to increase the field - How do you incorporate the 'parasitic resistance' of the wire that varies by wire gauge/composition etc. Lastly, this is a very small inductor (~.5 inches long) are there any tips for creating a winding apparatus...preferably with a turn counter.