Magnetic Flux Calculator

Calculate the magnetic flux density in Tesla from various input values. Magnetic flux density describes how strongly a magnetic field penetrates an area and is a key physical quantity, especially in electrical engineering and physics. The calculation is based on the formula B = Φ / A, where Φ (the Greek letter Phi) is the magnetic flux in Weber, B is the magnetic flux density in Tesla, and A is the area. The unit Tesla is defined as 1 Tesla equals 1 Weber per square meter, which directly describes the magnetic flux density. The alternative representation using the SI base units for Tesla is 1 kilogram per ampere per second squared, kg/(As²). While physically equivalent, this has no direct relevance for the practical calculation of the flux density itself.
Please enter two of the three values: magnetic flux, area, or flux density. The third value will be calculated.

Example for calculating the magnetic flux density in a small electric motor: Assuming the magnetic flux through the pole area of ​​the motor is 0.005 Weber and the effective pole area measures 0.01 square meters, then the magnetic flux density is calculated as B = Φ / A, i.e., 0.005 Weber (5 milliwebers) divided by 0.01 square meters (100 square centimeters), which corresponds to a flux density of 0.5 Tesla. This value is typical for strong permanent magnets, such as those found in industrial electric motors or even in simple magnetic resonance imaging (MRI) scanners with low field strength. For comparison, a refrigerator magnet reaches about 0.005 Tesla, while high-performance MRI scanners generate flux densities of 1.5 to 3 Tesla.

Magnetic flux density is also important in sensor technology and energy engineering. Hall sensors use it to measure rotational speeds or positions, with flux densities in the millitesla range already providing precise signals. In transformer cores, typical values ​​are between 1.2 and 1.8 tesla to avoid saturation effects and optimize efficiency. Induction cooktops control the flux density precisely to generate eddy currents in the cookware, with local peak values ​​of up to 0.1 tesla occurring.