The magnetic flux per unit area is called as magnetic flux density. Magnetic flux density is denoted by B. The formula for magnetic flux density is Weber per metre square or Tesla.

Mathematically magnetic flux density is given by,

B= Φ/a

Where, B = magnetic flux density

Φ = magnetic flux

a = cross sectional area

The unit of magnetic flux is Weber, the unit of area is metre square so the unit of magnetic flux density is Weber per metre square which is also called as Tesla.