Orders of magnitude (magnetic moment)

This page lists examples of magnetic moments produced by various sources, grouped by orders of magnitude. The magnetic moment of an object is an intrinsic property and does not change with distance, and thus can be used to measure "how strong" a magnet is. For example, Earth possesses an enormous magnetic moment, however we are very distant from its center and experience only a tiny magnetic flux density (measured in tesla) on its surface.

Knowing the magnetic moment of an object ($\mathbf {m}$) and the distance from its centre ($r$) it is possible to calculate the magnetic flux density experienced ($\mathbf {B}$) using the following approximation:

$\mathbf {B} \approx \mu _{o}{\frac {\mathbf {m} }{2\pi r^{3}}}$,

where $\mu _{o}$ is the constant of vacuum permeability.

Examples

Magnetic moment strength (from lower to higher orders of magnitude)

Factor (m2⋅A)	Value	Item
10−45	9.0877×10−45 m2⋅A	Unit of magnetic moment in the Planck system of units.
10−27	4.3307346×10−27 m2⋅A	Magnetic moment of a deuterium nucleus
10−26	1.4106067×10−26 m2⋅A	Magnetic moment of a proton
10−24	9.284764×10−24 m2⋅A	Magnetic moment of a positron
	9.274…×10−24 m2⋅A	Bohr magneton
10−18	0.65–2.65 nm2⋅A (1 nm2⋅A = 10−18 m2⋅A)	Magnetic moment of individual magnetite nanoparticles (20 nm diameter)
10-11	1.5×10−11 m2⋅A	Magnetic field of the human brain
	3.75×10−11 m2⋅A
10−5	7.99×10−5 m2⋅A	NIST YIG (yttrium iron garnet) standard 1 mm sphere for calibrating magnetometers (SRM #2852)
10−4	8.6×10−4 m2⋅A	Needle in a thumbnail-sized compass
10−3	7.909×10−3 m2⋅A	Neodymium-iron-boron disc in a typical mobile phone
10-1	0.1 m2⋅A	Magnetic field of a typical refrigerator magnet
	0.4824 m2⋅A	Neodymium-iron-boron (strongest grade) disc the same size as a US Penny
100	1.17 m2⋅A	Neodymium-iron-boron N35 magnet of 1 cubic centimeter in volume
	1.42 m2⋅A	Neodymium-iron-boron N52 magnet of 1 cubic centimeter in volume
103	5.937×103 m2⋅A	A bowling ball made of neodymium-iron-boron (strongest grade)
106	5×106 m2⋅A	Any magnet able to produce 1 tesla one metre away from its centre
1019	4×1019 m2⋅A	Magnetic field of Mercury
1020	1.32×1020 m2⋅A	Magnetic field of Ganymede
1022	6.4×1022 m2⋅A	Earth's magnetic field
1024	2.2×1024 m2⋅A	Magnetic field of Neptune
	3.9×1024 m2⋅A	Magnetic field of Uranus
1025	4.6×1025 m2⋅A	Magnetic field of Saturn
1027	1.55×1027 m2⋅A	Magnetic field of Jupiter
1028	1×1028 m2⋅A	Magnetic moment of a star or, equivalently, a white dwarf or a magnetar
1029	1×1029 m2⋅A
1030	1×1030 m2⋅A

See also

• Orders of magnitude (magnetic flux density)