How long does it take for a magnet to lose its power and become demagnetized?

The time it takes for a magnet to lose its power and become demagnetized depends on factors like the material of the magnet and how it is used. In general, permanent magnets can retain their magnetism for a long time, even decades or centuries. However, external factors like high temperatures, strong magnetic fields, or physical damage can cause a magnet to lose its power more quickly.