Enter the magnetic field strength and total area into the calculator to determine the total magnetic flux. This calculator can determine any of the variables in the formula below given the rest of the variables are known.

Magnetic Flux Formula

The following equation can be used to calculate a magnetic flux.

F = B * A * cos ( a ) 
  • Where F is the magnetic flux (webers)
  • B is the magnetic field (teslas)
  • A is the area (m^2)
  • a is the angle between the magnetic field and area (use 90 if no angle given)

To calculate a magnetic flux, multiply the magnetic field strength by the area, then multiply by the cosine of the angle between the field and area.

Magnetic Flux Definition

A magnetic flux is defined as the total strength of the magnetic field that passes through any given area.

Magnetic Flux Example

How to calculate magnetic flux?

  1. First, determine the magnetic field.

    Measure the strength of the magnetic field.

  2. Next, determine the total area.

    Calculate the total area the magnetic field is moving through.

  3. Next, determine the angle.

    Calculate the angle between the magnetic field and the area.

  4. Finally, calculate the magnetic flux.

    Calculate the magnetic flux using the formula above.


What is magnetic flux?

Magnetic flux is a measure of the total magnetic field that passes through an area. In other words, it’s the strength of the field times the total area that the field is acting across.

What is an electric field?

An electric field is a field producing a force due to the flow of electrons.