**Magnetic dipole** **moment **is defined as the product of pole strength and the distance between the two poles.

Let a → distance between the poles also called magnetic length,

and m → strength of each pole.

Thus, magnetic dipole moment, p_{m} is given as

p_{m} = ma

_{ }_{pm} is vector quantity directed from south to north pole.

S.I units of p_{m} are joule/tesla or ampere metre^{2.}