A number of different units for expressing magnetic dipole moment (hereafter simply “magnetic moment”) are commonly seen in the literature. It can be almost an impossibility, for example, to write dow...A number of different units for expressing magnetic dipole moment (hereafter simply “magnetic moment”) are commonly seen in the literature. It can be almost an impossibility, for example, to write down a list of the magnetic moments of the planets in order of increasing magnetic moment if one refers to the diverse literature in which the moments of each of the nine planets are quoted in different units. This chapter explores some of these aspects of magnetic moment.