# How to determine permeability of unknown cores - Online Calculator

#### How to find permeability of unknown toroidal core

If there is a toroid core of unknown permeability, wind up 5..20 turns of insulated copper wire on it (you have to evenly distribute the winding around the core), then measure the inductance of the coil. Enter measured inductance, number of turns and dimension of the toroid core in the fields below. All dimensions in mm
Measured inductance value L, μH =
Number of turns, N =
Outer Diameter of the core, D =
Inner diameter of the core, d =
Height of the core, h =
Dimensions and number of turns
Permeability, μ =

#### Toroidal core inductance Calculator Online

This online calculator can help you to calculate inductance, inductance factor and other parameters of a coil with a core made of ferrite or a similar material. Just enter dimensions, permeability of a core and number of turns in the fields below. All dimensions in mm
Outer Diameter of the core, D =
Inner diameter of the core, d =
Height of the core, h =
Permeability of the core material, μ =
Number of turns, N =
Inductance L, μH =
Effective core area, mm2 =
Effective core length, mm =
Effective core volume, mm3 =
Flux Density, B/I =
Inductance Factor, nH/N2 =