In electromagnetism, the current density is the amount of charge per unit time that flows through a unit area of a chosen cross section. The current density vector is defined as a vector whose magnitude is the electric current per cross-sectional area at a given point in space, its direction being that of the motion of the charges at this point. In SI base units, the electric current density is measured in amperes per square metre.
It gives the amount of current flowing across the given area.
Current Density Formula is expressed as,
J = I / A
I denote the current flowing through the conductor in Amperes and
A denotes the cross-section area in m2
Current density is expressed In A/m2