What is the Formula of Magnetic Susceptibility?

Formula:

Xm=I/H

It is the ratio of two quantities with the same units, so magnetic susceptibility has no unit.

The value of magnetic susceptibility depends on nature of material and temperature.

Mathematical Definition

If H=1

then

Xm=I

So magnetic susceptibility is the intensity of magnetization developed in the material when placed in a magnetising field of unit strength.