What Is the Gauss Rating for a Strong Magnet?

By J.T. Barett

The gauss is a measure of the strength of magnetic fields, relating force, length and electric current. It is used to conveniently measure weak fields, such as a small permanent magnets. Because it's a small unit, strong magnets will result in large measurements in gauss.


The gauss is a unit of magnetic field strength named after mathematician Carl F. Gauss. It's useful for dealing with relatively weak magnetic forces. The Earth's magnetic field measures a few gauss.

Magnet Strength

The stronger the magnet, the denser its magnetic field. Its field produces forces in other magnets and in metals.

Permanent Magnets

Currently, the strongest permanent magnets are those made with rare-earth metals such as neodymium. Their magnetic strength can be more than 14,000 gauss. This figure can also be stated as 14 Kilogauss (KGs).


Magnets used in Magnetic Resonance Imaging (MRI) machines are electromagnets that are supercooled with liquid helium. They are the strongest magnets in regular use, running 20,000 to 70,000 gauss.


Special magnets are used in scientific research to test the limits of magnet construction techniques and materials. The strongest experimental magnets run about 45 tesla, or 450,000 gauss.

About the Author

Chicago native J.T. Barett has a Bachelor of Science in physics from Northeastern Illinois University and has been writing since 1991. He has contributed to "Foresight Update," a nanotechnology newsletter from the Foresight Institute. He also contributed to the book, "Nanotechnology: Molecular Speculations on Global Abundance."