Toroid Inductance Calculator


About Toroid Inductance Calculator (Formula)

The Toroid Inductance Calculator is a tool used in electrical engineering to estimate the inductance of a toroidal (doughnut-shaped) coil. It helps in designing and analyzing circuits that utilize toroidal inductors. The calculation of toroid inductance involves the following formula:

Inductance (L) = (μ₀ * N² * A) / l


  • Inductance (L) represents the inductance of the toroidal coil, typically measured in henries (H).
  • μ₀ denotes the permeability of free space, approximately equal to 4π × 10⁻⁷ H/m.
  • N refers to the number of turns or windings in the coil.
  • A represents the cross-sectional area of the toroid’s magnetic core, usually measured in square meters (m²).
  • l denotes the average length of the magnetic path through the toroid’s core, typically measured in meters (m).

To calculate the toroid inductance, multiply the product of μ₀, N², and A by the reciprocal of the average magnetic path length, l.

It’s important to note that the cross-sectional area (A) and the average magnetic path length (l) should be measured along the path of the magnetic flux through the toroid’s core.

The Toroid Inductance Calculator assists engineers and enthusiasts in determining the inductance of toroidal coils, which are commonly used in various applications such as power supplies, transformers, and inductors for electronic circuits. By accurately estimating the inductance, designers can select appropriate components and analyze circuit behavior to achieve desired electrical characteristics.

Please note that the toroid inductance formula assumes ideal conditions and does not account for factors such as magnetic saturation, proximity effects, and winding capacitance, which may affect the actual inductance in practical scenarios.

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