Inductor calculator

An inductor is an element of an electrical circuit with a high inductance, with low capacitance and active resistance. They are used:

  • In frequency filters, for example, in acoustic systems for dividing a signal by frequencies for reproduction on corresponding speakers, or filtering electromagnetic interference.
  • In power sources, for example, to turn on LEDs from a single battery, where it is used as an energy storage device and to increase (lower) the voltage. In this case, this source is called a pulse transformerless voltage converter.
  • In radio transmitting devices, as an element of the oscillatory circuit tuned to the desired frequency in other devices. In this case, you can choose the appropriate capacitor frequency.

The coil is a wire wound on a frame in the form of a spiral, and the winding can be single-layer or multi-layer, coil to coil or with distance. They come in various types and forms, for example, without a core they have a small inductance, and with a core it increases significantly. This is due to the magnetic permeability of the material. The shape of the core can be different, distinguish armor, rod and toroidal.

To improve the overall dimensions, the coils are wound on a ferrite ring - this option is called the toroidal winding method.

How to calculate the coil in an online calculator and manually? Its parameters are affected by the number of turns (wire length), the presence and material of the core. The shape of the latter is selected on the basis of other requirements, such as dimensions - they affect the possibility of the location of the element in the housing. Our online calculator allows you to calculate the coreless inductor using the Maxwell elliptic integral method:

Required Inductance L
Frame diameter D
Winding length l
Copper wire diameter d
Insulation wire diameter k
Number of turns ω
Number of layers N
Coil Thickness with
* Wire length Lw
** Coil Resistance Ω

But you can do it yourself. Using the calculation formula, knowing the inductance of the coil:

Formula for calculating


  • D is the diameter of the coil;
  • N is the number of turns;
  • h is the height of the frame;
  • g is the thickness of the word (winding depth);

The advantages of an online calculator over this formula are quick and easy calculations. It is necessary to make the necessary inductance, the diameter of the frame and the length of the winding. After that, you must determine what kind of wire you have, measure the diameter of its core and, if it is insulated, the outer diameter of the insulation.

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