# Encyclopedia Magnetica™

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conversion_between_cgs_or_gaussian_to_si_magnetic_units

# Conversion between CGS or Gaussian to SI magnetic units

This section is an interactive calculator.
→ Multiply CGS quantity by Factor to obtain SI quantity1)2), CGS·F = SI
← Divide SI quantity by Factor to obtain CGS quantity, , CGS = SI / F
CGS quantity Units Factor F SI quantity Units
flux density $B$ (G) $10^{-4}$ flux density $B$ (T)
magnetic field strength $H$ (Oe) ${10^3}/{4π}$ magnetic field strength $H$ (A/m)
volume susceptibility $χ$ or $κ$ (unitless), (emu/cm3) a $4π$ volume susceptibility $χ$ or $κ$ (unitless)
mass susceptibility $χ_ρ$ or $κ_ρ$ (cm3/g), (emu/g) a $4π·10^{-3}$ mass susceptibility $χ_ρ$ or $κ_ρ$ (m3/kg)
molar susceptibility $χ_{mol}$ or $κ_{mol}$ (cm3/mol), (emu/mol) a $4π·10^{-6}$ molar susceptibility $χ_{mol}$ or $κ_{mol}$ (m3/mol)
magnetisation $M$ or
volume magnetisation c
(Oe) or
(emu/cm3) a
${10^3}$ magnetisation $M$ (A/m)
magnetisation $M$ or
intensity of magnetisation $I$
(G) or
(emu/cm3)
$4π·10^{-4}$ magnetic polarisation $J$ (T)
magnetisation $4π·M$
volume magnetisation $4π·M$
(Oe) or
(G)
${10^3}/4π$ magnetisation $M$ (A/m)
intrinsic induction $B_i$ or $4π·M$ (G) $10^{-4}$ magnetic polarisation $J$ (T)
magnetisation $M$ (per unit) ($μ_B/$atom), ($μ_B/$unit) $1$ b magnetisation $M$ (per unit) ($μ_B/$atom), ($μ_B/$unit)
magnetic dipole moment $m$ or $μ$ (erg/G) or (emu) $10^{-3}$ magnetic dipole moment $m$ or $μ$ (J/T) ≡ (A·m2)
demagnetising factor $N$ (unitless) $1/4π$ demagnetising factor $N$ (unitless)
permeability $μ$ (unitless) $4π·10^{-7}$ absolute permeability $μ$ (H/m)
relative permeability $μ_r$ not defined no factor relative permeability $μ_r$ (unitless)
magnetic flux $Φ$ (Mx) $10^{-8}$ magnetic flux $Φ$ (Wb)
magnetomotive force $F$ (Gb) $10/4π$ magnetomotive force $MMF$ (A) or (A-turn)
volume energy density $W$ or $E$ (erg/cm3) $10^{-1}$ volume energy density $W$ or $E$ (J/m3)
(mass) magnetisation $M$ or $σ$ (emu/g) $1$ magnetic moment per mass (A·m2/kg) ≡ (J/(T·kg))

Notes:3)4)

• a In this notation 'emu' is used not as a proper physical unit, but rather to indicate the type of units. In some cases susceptibility can be recalculated if 'emu' is replaced by cm3.
• b $μ_B$ denotes the Bohr magneton, which itself has a different unit in CGS and SI systems, but the “per unit” value scales in the same way in both systems, hence the conversion factor is unity.
• c Magnetic dipole moment per unit volume.

## oersted to A/m

 $H$ (Oe) = $\frac{1000}{4·π}· H$ (A/m) H (Oe) =         H = (A/m) (A/cm) (kA/m) (MA/m)

## A/m to oersted

 $H$ (A/m) = $\frac{4·π}{1000}· H$ (Oe) H = (A/m) (A/cm) (kA/m) (MA/m)         H (Oe) =

## MGOe to kJ/m³

 $B·H$ (GOe) = $\frac{1000}{4·π·10000}· H$ (J/m³) B·H (MGOe) =         B·H = (J/m³) (kJ/m³)