Magnetic induction, B

The flux density is the number of magnetic field lines that run through a certain point on a surface. Another indication is magnetic induction. The unit of magnetic flux is the Weber (Wb). The SI unit is T (tesla), which corresponds to one Weber per square metre (Wb/m2). The unit in the CGS system is G (gauss). 1 tesla is equal to 10,000 gauss.
At any point in a magnetic field, the magnetic flux density can be seen as a vector in the direction of the field, the magnitude of which corresponds to the Lorentz force that an electric wire experiences when it is aligned perpendicular to the field lines.

The higher the flux density, the stronger the magnet is at this point and the better it can hold iron particles at this point. In a homogeneous field, in which the surface is perpendicular to the magnetic field lines, it is the product of the surface and the magnetic field strength. 

The magnetic flux density is usually represented in formulae by the symbol, a (pseudo) vector field.

FluxΦ = B-AΦ = magnetic flux (Wb)
B = magnetic field strength (T)
A = surface area (m2)

Goudsmit calculates the flux density using the finite element method (FEM calculation). This enables us to develop the right magnet for a new or existing product or application faster and better. You can read more about magnet calculations and simulations here.