What is the expression for determining the magnetic flux?

Magnetic flux Ф is called a physical quantity equal to the product of the magnetic induction B of the magnetic field by the area of the contour S, which penetrates the magnetic field, and by the cosine of the angle between the perpendicular to the plane and the vector of magnetic induction: Ф = В * S * cosα.
The unit of measurement of magnetic flux is weber (Wb).
A magnetic flux of 1 Wb is such a flux in which the area bounded by a contour of 1 m ^ 2 penetrates a magnetic induction of 1 T and which is located perpendicular to the lines of force of the magnetic field.