How often does Earth's magnetic field change direction?

Earth's magnetic field changes direction once in every two million years. The magnetic field of the earth is the geomagnetic field that stretches from the earth to the outer space.

This magnetic field is generated because of the convection currents that are generated by the iron that melts inside the core of the earth. This magnetic field changes very slowly over a period of several years and only slightly which means that those living on the earth do not come to know about this change.

In the last 10 million years, there have been, on average, 4 or 5 reversals per million years.