How this calculator works
For an isotropic linear material, magnetization is proportional to magnetic field strength H. This makes relative permeability equal to one plus volume susceptibility. The conversion assumes the same operating point and SI susceptibility convention. Ferromagnets have field-dependent, history-dependent and frequency-dependent permeability, so there is no universal iron or ferrite preset. The perfect-diamagnet option is an ideal flux-exclusion limit and does not model a real superconductor critical field.
Formula
B = mu H; mu = mu0 mur; M = chi H; mur = 1 + chi. CODATA 2022 mu0 = 1.25663706127e-6 H/m.
Worked example
Relative permeability 1 gives mu = 1.25663706127e-6 H/m and susceptibility 0. Susceptibility 9 gives relative permeability 10 and mu = 1.25663706127e-5 H/m.
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Frequently asked questions
Is permeability measured in henries?
Absolute permeability uses henries per metre. Inductance uses henries; they are different quantities.
Why are there no fixed iron values?
Iron permeability changes substantially with field, purity, processing, temperature and magnetic history. Enter a measured value for your operating point.
Can susceptibility be negative?
Yes. Diamagnetic materials have negative susceptibility; this linear passive model requires chi no smaller than -1.