How are magnets rated?

Magnets are characterized by three main features:

• Residual Induction: With the symbol Br, measured in Gauss, this is an indication of how strong the magnet can be.
• Forced Force: Given the symbol Hc and measured in Oersteds, this is an indication of how difficult it is to demagnetize the magnet.
• Maximum Energy Product: With the symbol BHmax, measured in Gauss-Oersteds, this is an indication of the volume of magnetic material required to project a given magnetic flux.