In the current theory of magnetism, magnetic flux relates to the direction perpendicular to the magnetic force per unit.

    If that sounds confusing, don't worry. Faraday's law and magnetism, in general, is complicated stuff, but we're going to help you tackle it.

    In this article, we've answered the top questions we hear about magnetic flux, including how its measured and what its used for.

    If the math gets difficult, try our free magnetic flux converter to get accurate conversions in a snap.


    Why use a magnetic flux converter?

    When you come across magnetic flux, it can be expressed in a variety of units and measurements.

    A Magnetic Flux Converter can give you a hand with the tough conversions.

    If you don't want to go through the hassle of converting yourself, just type in your units and numbers, then watch the answer appear right away.

    Even if you decide to do the math by hand, it's a smart idea to check your work with a reliable conversion calculator.

    What is magnetic flux?

    To better understand magnetic flux, it's best to start with the meaning of regular flux.

    When someone uses "flux" in science, they're talking about the number of particles or substances flowing through an area during a certain time frame.


    Imagine a screen sitting stationary in a rainstorm.

    If we wanted to measure the flux of the area within the screen, we'd consider how many raindrops pass through the screen in a given time.

    So let's apply that to magnetism.

    Magnetic Flux

    In simple terms, everyone can actually understand, magnetic flux refers to the amount of the magnetic field that passes through that "screen".

    It's measuring the strength of the magnetic field in that area.

    Now, let's dive a little deeper.

    Magnetic Field Vectors

    Unlike a screen sitting in a rainstorm, measuring the magnetic flux doesn't count particles (like raindrops), but instead measures the magnetic field vectors.

    The magnetic field contains vector quantities. These vector quantities indicate the direction and strength of the magnetic field.

    So when we measure magnetic flux, we are analyzing the magnetic field vectors in a certain area.


    Magnetic flux refers to the amount of the magnetic field vectors flowing through a certain area. It's measuring the strength of the magnetic field in that given range.

    How is it measured?

    There are a few different scenarios you could encounter when measuring magnetic fields:

    1. If you measure an area far from the magnetic field, the flux is lower because the field's strength is weakened.
    2. If you measure perpendicular and very close to a magnet, the flux increases.
    3. Zero flux occurs when the area measured is parallel to the magnetic flow.

    To comprehend this, think of a screen sitting in a rainstorm. If we placed our screen parallel to the rain's direction, no drops would pass through it.

    Likewise, if we measure an area parallel to the magnetic field, no field vectors can be analyzed.

    Measurement Devices

    Although many are painful on the budget, devices can be utilized to measure magnetic flux. Most often, a Gauss meter is employed. There are several types.

    Some examples include:

    • Fluxmeters, which contains a coil that moves freely between the poles of a magnet. This movement induces a voltage on a stationary coil, which proportionately indicates the change in flux.

    • Hall Effect meters measure voltage to determine the flux. When a magnetic field crosses an electrical current, it produces a measurable voltage.

    • Proton meters utilize nuclear magnetic resonance to measure the strength of the magnetic field. They are one of the most accurate devices available.

    • Traditional gaussmeters are either scalar or vector. Scalar meters measure magnitude while vector devices read magnitude and field direction.

    What are its uses?

    So why, you might be wondering, would anyone want to know about magnetic flux?

    It turns out, there are a plethora of reasons to measure this type of flux.

    Engine Mechanics

    Magnetic field is an important consideration in motors.

    In fact, many motors have magnets mounted on the surface of their rotors. The magnets provide variable frequency and voltage, making them useful for variable-speed drives.

    To make everything align correctly, engineers must anticipate the magnetic field's strength. To do this, they measure the magnetic flux.


    Because magnetism and voltage are so closely interlinked, it probably comes as no surprise flux is used in electricity.

    Through electromagnetic induction, we can manipulate the magnetic field in a circuit to induce an electromagnetic field.

    In order to understand where and how to manipulate the field, measurements (including magnetic flux) are recorded.

    Studying the Earth

    Earth's own magnetic field makes measuring flux important in understanding natural cycles.

    For instance, cycles in Earth's interior and around the poles are better understood by analyzing flux.

    Recently, magnetic flux was used to study convection currents inside the Earth and the dynamo effect.

    What's the standard unit of magnetic flux?

    Magnetic flux is measured with the Weber and Maxwell units. The shorthand abbreviations are Wb and Mx.

    In some cases, you may encounter these units in smaller or larger margnitudes, like the microweber, for example.

    There's also other common hand expressions that are used such as volt seconds and tesla square meters.

    How do you convert magnetic flux?

    You may be asked to convert the SI unit (Weber) to one of the following:

    • Volt second (V·s)
    • Tesla square meter (T·m2)
    • Microweber (uWb)
    • Maxwell (Mx)

    It's not nearly as difficult as you would think. In fact, two of the above involve no math whatsoever.


    The Maxwell is the centimeter-gram-second (CGS) variant of the metric system.

    To convert Wb to Mx, use the following formula:

    Mx = Wb (1 · 108 Mx)/1 Wb

    This formula is saying 1 Weber is equal to 108 Maxwell.


    To convert Weber to microweber, use this equation:

    uWb = Wb (1 · 10-6 uWb)/1Wb

    As you have probably guessed, 1 uWb = 10-6 Wb.

    Volt Second and Tesla

    It only gets easier from here.

    One Weber is equal to one volt part second. Likewise, one Weber is equal to one Tesla square meter.

    1 Wb = 1 V·s

    1 Wb = 1 T·m2

    Is there a formula for magnetic flux?

    Yes. And calculating magnetic flux isn't as hard as you might think. It is calculated through the following equation:

      Φ = B · A · cosθ

    It might look like a different language. Don't worry. We'll break it all down for you.

    This equation translates to "magnetic flux (Φ) equals the magnitude field vector (B) times the surface being measured (A) times the cosign of the surface's angle (cosθ)."

    If there is no angle:

      Φ = B · A

    Wrapping Up

    Hopefully this quick explanation and our magnetic flux calculator have been useful to you.

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