This article is from the Static Electromagnetic Fields and Cancer FAQ, by John Moulder firstname.lastname@example.org and the Medical College of Wisconsin with numerous contributions by others.
Static magnetic fields are generally measured in Tesla (T), milliTesla
(mT), and microTesla (microT) where 1000 mT = 1 T, and 1000 microT = 1
mT. In the US, fields are sometimes still measured in Gauss (G) and
milliGauss (mG), where 10,000 G equals 1 T (1 G = 100 microT; 1 microT =
10 mG). In the FAQ, mT (milliT) will be the preferred term.
Magnetic fields can be specified in either magnetic flux density or
magnetic field strength. In the US and Western Europe field strengths
are usually specified in units of magnetic flux density (Tesla or
Gauss). In some of the Eastern European literature, however, magnetic
fields are specified in Oersteds (Oe), which are units of magnetic field
strength. When dealing with exposure of non-ferromagnetic material,
such as animals or cells, magnetic flux density and magnetic field
strength can be assumed to be equal, so 1 Oersted = 1 Gauss = 100