Gapped Core Inductance Calculator

The Gapped Core Inductance Calculator will calculate the Inductance per turn, Inductance and flux density per amp with full calculations and formula

Gapped Core Inductance Calculator
Gapped Core Inductance Results (detailed calculations and formula below)
The Inductance per turn2 (Al) is nH
The Inductance (L) is uH
The Flux Density per Amp (B/I) is gauss/A
Inductance per turn calculations
Al = 4π × Ae/Le/μr + Lg
Al = (4 &ties; ) × // +
Al = × / +
Al = /
Al =
Inductance calculations
L = Al × N2/1000
L = × 2/1000
L = × 2/1000
L = /1000
L =
Flux Density per Amp calculations
B/I = 0.4π × N/Le/μr + Lg
B/I = (0.4 × ) × // +
B/I = × / +
B/I = /
B/I =
Calculator Input Values
Core length (Le)
Gap area (Ae)
Gap length (Lg)
Relative permeability (μr)
Number of turns (N)
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Inductance per turn Formula and Calculation

Al = 4π × Ae/Le/μr + Lg

Inductance Formula and Calculation

L = Al × N2/1000

Flux Density per Amp Formula and Calculation

B/I = 0.4π × N/Le/μr + Lg

Welcome to our tutorial on the Gapped Core Inductance Calculator. In the field of electrical engineering, inductors play a crucial role in various applications, including power electronics, signal processing, and electromagnetic compatibility. The gapped core inductance is an important parameter used to design and analyze inductors with magnetic cores that contain deliberate gaps. In this tutorial, we will introduce the concept of gapped core inductance, discuss interesting facts about inductors and magnetic cores, explain the formula used for its calculation, and provide a real-life example to demonstrate its application.

Interesting Facts about Inductors and Magnetic Cores

Before we delve into the details of the gapped core inductance calculator, let's explore some interesting facts about inductors and magnetic cores:

  • An inductor is a passive electronic component that stores energy in a magnetic field when a current passes through it.
  • Inductors are commonly used in electronic circuits for functions such as energy storage, noise filtering, and frequency selection.
  • Magnetic cores, made from materials like iron, ferrite, or powdered metal, are used to enhance the magnetic field and increase the inductance of an inductor.
  • The addition of deliberate gaps in magnetic cores can modify the inductance and other electrical properties of the inductor.
  • Gapped core inductors offer advantages such as improved linearity, reduced saturation, and enhanced stability in certain applications.

The Formula for Gapped Core Inductance Calculation

The calculation for gapped core inductance depends on the physical parameters of the inductor and the magnetic core. The formula is as follows:

Gapped Core Inductance (L) = (µ0 × µr × N2 × A) / (leff + g)


  • L is the gapped core inductance in henries (H)
  • µ0 is the permeability of free space (approximately 4π × 10-7 H/m)
  • µr is the relative permeability of the magnetic core material
  • N is the number of turns in the inductor
  • A is the cross-sectional area of the magnetic core in square meters (m2)
  • leff is the effective magnetic path length in meters (m)
  • g is the length of the air gap in meters (m)

Example: Application of Gapped Core Inductance Calculation

Let's consider an example to illustrate how the gapped core inductance calculation is used in real life:

Suppose we have an inductor with a magnetic core made of ferrite material. The inductor has 100 turns, a cross-sectional area of 0.001 square meters, an effective magnetic path length of 0.05 meters, and an air gap length of 0.01 meters. The relative permeability of the ferrite material is 200.

To calculate the gapped core inductance, we can substitute the given values into the formula:

Gapped Core Inductance (L) = (µ0 × µr × N2 × A) / (leff + g)

Substituting the values:

L = (4π × 10-7 H/m × 200 × 1002 × 0.001 m2) / (0.05 m + 0.01 m)

L ≈ 5.026 × 10-4 H

In this example, the calculated gapped core inductance is approximately 0.0005026 H.

The gapped core inductance calculation is crucial in the design and analysis of inductors with magnetic cores containing deliberate gaps. By understanding the inductance value, engineers can determine the performance characteristics of the inductor and ensure it meets the requirements of the desired application. Gapped core inductors find applications in various fields, including power electronics, audio systems, and telecommunications.

For example, in power electronics, gapped core inductors are used in switch-mode power supplies (SMPS), where they provide energy storage, noise filtering, and voltage regulation. The calculated inductance helps determine the efficiency, ripple current, and overall performance of the SMPS. In audio systems, gapped core inductors play a role in crossover networks, where they separate audio frequencies and direct them to the appropriate speakers. The inductance value affects the frequency response and overall sound quality of the audio system.

Furthermore, the gapped core inductance calculation assists in the design optimization process. By adjusting the parameters such as the number of turns, core material, and gap length, engineers can fine-tune the inductance to achieve desired characteristics, such as higher linearity, reduced saturation, and improved stability. This enables the design of inductors tailored to specific applications, ensuring optimal performance and reliability.

In summary, the gapped core inductance calculator is a valuable tool for engineers involved in the design and analysis of inductors with magnetic cores containing deliberate gaps. By understanding the concept, formula, and real-life applications of gapped core inductance, engineers can accurately calculate the inductance value and optimize the performance of their designs. The gapped core inductance calculation plays a crucial role in various industries, enabling the development of efficient and reliable electronic systems. So, the next time you work on an inductor design or encounter an electronic device utilizing inductors, remember the importance of the gapped core inductance calculation and its impact on performance and functionality.