Magnetics · linear model

Magnetic reluctance & inductance

Uniform core and air gap, constant relative permeability, negligible leakage and no fringing. Enter effective geometry and material data; the defaults are an arithmetic example, not a core recommendation.

Core path length (mm) Effective area (mm²) Relative permeability Total air gap (mm) Turns Current (A)

Equations & limits

ℜ = le/(μ0 μr Ae) + lg/(μ0 Ae); L = N²/ℜ; B = LI/(N Ae); E = ½LI², with μ0 = 4π × 10⁻⁷ H/m. Geometry is converted to SI before calculation.

Flux density is the linear-model value. It is not a nonlinear saturation simulation. Compare it with the actual material’s B–H curve at temperature; this tool gives no core-loss, winding-loss, temperature-rise or current-rating result.

Material definitions and effective geometry: TDK ferrite definitions.