Gapped Core Inductance Calculator

Gapped Core Inductance Calculator

Gapped Core Inductance Calculator is a tool used to calculate inductance in the presence of voids in a core.

Gapped Core Inductance Calculator is a tool used to calculate inductance in the presence of voids in a core. This calculator calculates the inductance value taking into account the size, material and shape of the voids in a given core. The voids can change the inductance by affecting the magnetic properties of the core. This calculator is a useful tool for engineers and designers in the process of determining and optimizing inductance values in the design of electrical and electronic circuits.

When using the online gapped core inductance calculator you can calculate by entering: acore length, gap area, gap length, relative permeability and number of turns.



Core length
Gap area
Gap length
Relative permeability
Number of turns
Share by Email

    1 Number of Calculations Used Today


    • Al = (4Ï€*Ae) / ((le/μr)+lg)
    • L = Al*N210-3
    • B/I = (0.4Ï€*N) / ((le/μr)+lg)


    • Al = Inductance per turn2
    • N = Number of turns
    • Ae = Gap area
    • Le = Core length
    • μr = Relative permeability
    • Lg = Gap length
    • B/I = Flux Density per Amp


    How to Calculate Gapped Core Inductance?

    The following steps are followed when calculating the gapped core inductance:

    1. Determination of Core Properties: The first step is to determine the properties of the core used. These properties include factors such as the material of the core, its dimensions (such as diameter and height), the size and position of the cavities.
    2. Entering Core Parameters: The core parameters required for the calculation are entered into the calculator. These parameters include the material of the core, the size and position of the gaps, the number and diameter of wires, etc.
    3. Inductance Calculation: Based on the core parameters entered, the inductance of the cavity core is calculated. This calculation is usually done using a formula or mathematical expression.
    4. Analysis of Results: The obtained inductance value is analyzed and changes are made to the core design or parameters if necessary.

    There are various mathematical formulas and calculation methods to directly calculate the gapped core inductance. These formulas may vary depending on the geometry and material of the core and the location of the cavities. Therefore, it is important to choose the right formula and calculation method to obtain accurate results.

    What is Gapped Core Inductance?

    Gapped core inductance refers to the condition in which the inductance of an inductor (coil) in an electrical circuit varies due to voids or air gaps in the core. Inductance is defined as the response of an inductor to a unit current change and is usually measured in henry (H) units.

    Gaps in the core change the path of the magnetic field through the core and therefore affect the inductance value. Cavities reduce inductance by pushing some of the magnetic flux density out of the field. Therefore, the inductance of a core filled with voids will be lower than the inductance of a solid core of the same material and dimensions.

    Gapped core inductance is especially important in industrial electronics applications and power converters (for example: power supplies, inverters and transformers). An accurate inductance calculation ensures that electrical circuits operate correctly and can prevent unwanted overcurrent or voltage surges. Therefore, accurate calculation and evaluation of the gap core inductance is critical to the design and performance of electronic systems.

    Working Principle of Gapped Core Inductance

    The principle of operation of gapped core inductance is based on the fact that voids in the core affect the inductance by changing the path of the magnetic field. These voids push some of the magnetic flux density out of the field and therefore reduce the inductance of the core.

    Magnetic flux is a measure of the magnetic field generated by the flow of current in an inductor (coil). Some of the magnetic flux finds its way into the core of the inductor. However, gaps or air gaps in the core alter this path of the magnetic flux and push some of it out of the field. This causes the magnetic flux to travel less through the core and hence reduces the inductance.

    The gapped core inductance is determined by the effect of these voids, which change the path of the magnetic field and reduce the inductance. Therefore, the size, position and number of gaps significantly affect the inductance value of the core. The larger the gaps or the more gaps in the core, the more the inductance decreases.

    This principle of operation is important for the correct design of inductors and the determination of their inductance value. The calculation of the gapped core inductance ensures the correct operation of magnetic circuits and is important for optimizing the performance of electrical circuits.

    Applications of Gapped Core Inductance Calculation

    The gapped core inductance calculation has various uses. Some important uses are as follows:

    • Power Electronics Design: In the design of power converters (e.g., inverters, rectifiers, frequency converters), it is important to accurately calculate the inductance due to gaps in the core. Correct inductance values affect the efficiency and performance of power electronics circuits.
    • Magnetic Separators and Transformers: In magnetic separators and transformers, it is necessary to calculate the inductance accurately due to gaps in the core. This has a direct impact on the efficiency and reliability of transformers.
    • Ferrite and Toroid Inductors: Ferrite and toroid inductors are widely used in electronic circuits. In these types of inductors, it is important to calculate the effect of voids in the core on the inductance.
    • Radio Frequency (RF) Circuits: In radio frequency circuits, an accurate calculation of the inductance due to voids in the core affects the high-frequency performance of the circuits. Inductance values of inductors used in RF circuits must generally be very accurate.
    • Audio and Video Equipment: In audio and video equipment, especially devices that process high quality audio or video signals, it is important to accurately calculate the gap core inductance. This affects the performance of the devices and the audio/quality output.
    • Medical Devices: In many medical devices, precise control of magnetic fields is required. Gapped core inductance calculation is important to ensure the correct operation of medical devices.

    Besides these uses, gapped core inductance calculation plays an important role in various fields of electronics, electrical engineering and industrial applications. Determining the correct inductance values is critical to optimize the performance of electrical circuits and avoid unwanted problems.