What Does Gauss Mean & What Does Gauss Measure?
Many companies that work with magnets in manufacturing use the term “gauss” every day. It’s a common measurement in magnetic applications, but it is also often misunderstood — even by companies that rely on magnetic components.
The term “gauss” comes from Carl Friedrich Gauss, a German mathematician and physicist whose work helped advance the measurement and understanding of magnetism. Of course, you can probably get by without that particular trivia nugget. It’s more important to know what “gauss” actually refers to — and what it does not mean.
What does gauss mean?
Essentially, gauss is a unit commonly used to express magnetic flux density, or magnetic field B, at a specific location. In everyday magnet applications, people often use gauss as a practical way to describe local magnetic field intensity.
One gauss is defined as one maxwell of magnetic flux per square centimeter. Another way to think of it is in terms of flux density: how much magnetic flux passes through a given surface area.
A gauss reading does not necessarily tell you how far a magnetic field reaches. The field strength at a distance depends on several factors, including magnet size, shape, material, magnetization direction, air gap, and nearby steel or shielding.
In more technical terms, gauss describes magnetic flux density at a specific point. Because magnetic flux density is a vector field, both the magnitude and direction can vary from one location to another. That means a gauss reading taken at one spot on or near a magnet may be very different from a reading taken at another location.
Magnet pull strength vs. gauss
Gauss is different from magnet pull strength, and a higher gauss reading does not necessarily mean higher pull force.
A gauss reading is useful in applications where magnetic field level is the primary performance factor, such as sensor applications, reed switch activation, Hall effect sensors, and other field-sensitive designs. However, gauss level alone usually cannot be used to compare the strength of two magnets unless the magnets have the same geometry and material, and the readings are taken at the same location and distance from the magnet.
Pull strength depends on many additional factors, including magnet size, pole area, grade, shape, air gap, surface finish, contact area, and the thickness and composition of the steel target. For that reason, a small magnet may have a high surface gauss reading but relatively low pull force, while a larger magnet with a lower surface reading may produce greater holding force in the right application.
What does gauss measure?
In measurement terms, gauss, abbreviated as G or Gs, is the cgs unit of measurement for magnetic flux density, also known as magnetic induction. One gauss is defined as one maxwell per square centimeter.
The cgs system has largely been replaced in technical and scientific work by the SI system, which uses the tesla (T) as the unit for magnetic flux density. The conversion is simple:
1 tesla = 10,000 gauss
Okay, back to Earth.
Earth’s magnetic field at the surface is roughly 0.5 gauss, although the exact value varies by location. A small refrigerator magnet may measure many times higher than Earth’s magnetic field near its surface. At first glance, that could make it sound as though the refrigerator magnet is “stronger” than Earth’s magnetic field in every way, but that would be misleading.
A magnetic field can extend through space, but its strength decreases with distance. A refrigerator magnet may have a relatively high field very close to its surface, but the field drops off quickly. Earth’s magnetic field is much weaker locally, but it extends over a vast area.
That is why measurement location matters so much. It is also why air-shipment regulations evaluate magnetic field strength at a specified distance from the package. In many cases, the gauss level at that distance is very small and can only be measured with an accurate, sensitive gauss meter.
Magnetic field calculator
A calculation can help estimate magnetic field strength at a distance, but it may not account for every real-world condition, such as shielding, packaging, nearby steel, or the exact magnetization pattern of the magnet. Working out the calculation by hand can also be a long and difficult process.
Fortunately, Adams offers a shortcut: a free Magnetic Field Calculator that estimates both gauss level and pull force. Our calculations are based on the size and material type of an individual magnet, making it easier to evaluate magnetic performance before moving forward with a design or application.
Check out our
Magnetic Field Calculator
Learn how to use a gaussmeter
Understanding what gauss means is the first step. The next step is knowing how to measure it correctly.
Because magnetic flux density changes depending on probe position, distance, magnet geometry, and measurement direction, it is important to use consistent testing methods. For a practical overview, read our related post: How to Test a Magnet Using a Gaussmeter.
In that article, we explain what a gaussmeter is used for, how a gaussmeter works, the difference between transverse and axial probes, and tips for getting more repeatable magnetic field measurements.
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