What is Gauss? Magnetic Field Measurement Explained

Why this matters

When a manufacturer says a neodymium magnet is “13,500 Gauss”, they may be referring to the remanence of the magnetic material under idealised material conditions.

When a Gaussmeter is placed on the surface of a Q Magnet and records, for example, 2,500-3,500 G at a pole centre, that is also a B-field measurement, but it is a real-world surface measurement taken at a specific point and orientation on a finished multipolar device.

Both can be legitimate B-field figures. They are just not the same measurement.

Part 4: Why Does the Same Magnet Show Different Gauss Numbers?

This is probably the single most common source of confusion in magnetic therapy claims.

A person asks, “What is the Gauss of this magnet?” It sounds like there should be one simple answer. But there often is not, especially with multipolar magnets.

Take a Q Magnet and consider three different ways the word “Gauss” might be used.

1. Neodymium material remanence

N45 neodymium has an intrinsic remanence of approximately 13,200-13,700 Gauss, or 1.32-1.37 Tesla. This is a property of the magnetic alloy and is often where “13,500 Gauss” comes from in product descriptions.

This does not mean the user is being exposed to 13,500 G at every point around the finished therapeutic device.

2. Surface field at a pole centre

If you hold a Gaussmeter probe flat against the centre of one pole on a finished Q Magnet, you may record a surface reading around 2,500-3,500 G, depending on the model, probe, placement, and orientation.

This is a practical measurement of the finished device at one point.

3. Surface field near an interpole boundary

If you move the same probe to the boundary between adjacent poles, or rotate the probe to measure a different axis, the reading can change dramatically.

That is because a multipolar magnet is not designed to produce the same field everywhere across one face. It is designed so that North and South poles sit side by side, forcing the field to change direction over a short distance.

That rapid spatial change is the magnetic field gradient.

Gauss Measurement (Z-Axis)

Gauss Measurement (XY-Axis)

The key lesson

A zero reading in one axis does not necessarily mean there is no magnetic field at that point. It may mean the component being measured cancels in that particular orientation.

At the interpole boundary, the Z-axis component can read close to zero, while the XY-axis component can be strong. That same region is important because it is where adjacent poles interact and where the field changes direction most rapidly.

On a typical bipolar magnet, readings taken across the same face are usually much more similar because the field is relatively uniform across that face.

On a quadrapolar magnet, the alternating pole structure creates rapid changes in field direction and strength across the surface. That variation is not a defect. It is the observable signature of the multipolar field geometry.

So when someone asks, “What is the Gauss of a quadrapolar magnet?”, the honest answer is:

It depends where and how you measure it.

The better question is:

What field gradient does the magnet create, and where is that gradient positioned relative to the target tissue?

Part 5: The N Rating – N45, N52, and Maximum Energy Product

Alongside Gauss ratings, therapeutic magnet descriptions often feature grade designations such as N35, N45, or N52.

These refer to the neodymium magnet grade and describe the Maximum Energy Product, written as BHmax. This is a measure of how much magnetic energy the material can store per unit volume.

The unit is MegaGauss-Oersteds (MGOe) in CGS units, or kilojoules per cubic metre (kJ/m3) in SI units.

N52 is close to the theoretical maximum achievable with common neodymium-iron-boron alloys at room temperature.

But a higher N grade does not automatically mean a better therapeutic device.

BHmax is a material property. It tells you something about the magnetic material, but it does not fully describe the finished device, the field pattern, the depth of useful exposure, or the gradient at the treatment surface.

Actual field behaviour depends on:

• physical size and thickness of the magnet
• polarity configuration (bipolar, quadrapolar, hexapolar, octapolar, concentric)
• presence of a flux plate
• magnetisation precision
• distance from the target tissue
• probe position and orientation during measurement

An N52 magnet configured as a simple bipolar does not create the same localized field gradients as an N45 magnet configured as a multipolar array with a flux plate.

Q Magnets use N45 grade neodymium because it provides high field strength, good temperature stability, and reliable gradient generation without unnecessary brittleness and cost associated with the highest neodymium grades. Learn more about how Q Magnets work in practice.

The therapeutic question is not simply “What grade is the material?” It is “What useful tissue exposure does the finished device create?”

Part 6: The Gauss Falloff Problem – Why Proximity Is Everything

One of the most counterintuitive facts about magnetic fields is how quickly their strength falls with distance.

For an ideal point-source dipole, field strength falls approximately with the cube of distance (1/d3). Real magnets do not behave exactly like point sources, because geometry matters, but the practical principle remains the same:

magnetic fields weaken rapidly with distance.

A magnet that reads strongly at the surface may be dramatically weaker only a short distance away.

For example:

• A magnet reading 3,000 G at the surface will read much less at 10 mm distance.
• By 30 mm, the field will have fallen to a small fraction of the surface reading.
• At 1 metre, the field from a therapeutic magnet is usually negligible for practical purposes.

This is why direct placement matters.

A magnetic brace, wrap, or mattress pad may quote an impressive surface rating at the magnet face, but if the magnet is buried behind foam, fabric, padding, or distance, the field reaching the target tissue may be far lower.

This is also why Q Magnets are made in different sizes and depths of application. A superficial nerve or tendon may require a different device than a deep spinal structure, hip joint, or thick muscle region. For practical selection guidance, see which magnet to use.

But why does Earth’s 0.5 Gauss field move every compass?

Earth’s magnetic field is weak, but it is vast and relatively uniform at the scale of a compass. The compass needle is immersed in the field, and the field direction is consistent enough to align the needle.

A therapeutic magnet is the opposite.

It is powerful close-up, but highly localized. It does not influence from across the room. It depends on proximity, field geometry, and placement over the target tissue.

A simple analogy: a candle close to your hand can feel warm; move it a metre away and you barely feel it. The sun is far away but enormous, so it influences the whole planet. Local intensity and large-scale reach are very different things.

Part 7: The Therapeutic Window – Too Weak, Too Strong, or Just Right?

Understanding Gauss becomes clinically relevant when people ask, “How strong should a therapeutic magnet be?”

The simple marketing answer is often: stronger is better.

The research on magnetic field therapy suggests a more nuanced answer.

There appears to be a window of effectiveness for static magnetic field exposure. Below a certain threshold, there may be too little field at the target tissue to produce a measurable biological response. Above a different threshold, the expected response may not increase and may even diminish, depending on the model, tissue, timing, and exposure conditions.

Morris and Skalak edema studies

Two studies from the University of Virginia are often cited because they show why “stronger is better” is too simplistic.

In one study, researchers induced localized inflammation in rat hindpaws using histamine, then applied static magnetic fields of different strengths immediately after injury.

The 70 mT field reduced histamine-induced edema formation by approximately 40-65%. A 10 mT field also produced a significant reduction. But a stronger 400 mT field did not reduce edema in that model.

The same research also showed that timing mattered. Applying the field before injury, or after swelling had already peaked, did not produce the same effect. The field appeared most relevant when applied early in the inflammatory cascade.

A companion study found that continuous static magnetic field exposure in the 20-60 mT range altered microvessel enlargement after surgical intervention. Again, this suggests that exposure conditions, timing, and field strength matter.

What the therapeutic window means

The takeaway is not that there is one perfect Gauss number.

The takeaway is that biological response appears to be dose-dependent and context-dependent.

A useful framework includes:

• field strength at the target tissue, not just at the magnet surface
• distance from the magnet
• exposure duration
• field geometry
• magnetic field gradient
• tissue type
• timing relative to injury or sensitization
• placement accuracy

This is why Field | Dose | Placement matters.

Part 8: Field Gradients, MER, and Why Multipolar Design Matters

Even within the therapeutic window, the type of field matters as much as its strength.

This is where multipolar magnets diverge from the simpler world of bipolar magnets.

What is a magnetic field gradient?

A magnetic field gradient describes how quickly the magnetic field changes over distance. It is often expressed as dB/dx, meaning the change in magnetic flux density over a change in distance.

A field can be strong but relatively uniform. It can also be moderate in strength but changing rapidly over a short distance.

These are not the same.

A typical bipolar magnet has one North face and one South face. Across the same face, the field is often comparatively uniform. If you move a Gaussmeter across the surface, the reading may change, but usually not as dramatically as on a multipolar magnet.

A quadrapolar magnet places alternating North and South poles side by side on the same treatment face. At the boundary between adjacent poles, the field direction changes quickly across a short distance. That is where steep localized gradients are created.

Why gradients matter

The Vanderbilt/McLean research on static magnetic fields and sensory neurons suggested that field strength alone was not sufficient to explain the observed biological effects.

In laboratory studies using quadrupolar magnetic arrays, cultured sensory neurons positioned over specific regions of the field showed reversible changes in action potential firing. Other regions, including pole centres or the middle of the array, produced less effect.

The important concept was not simply the strongest Gauss point. It was the relationship between field strength, field direction, and field gradient.

Maximally Effective Region (MER)

The McLean/Vanderbilt research described a region called the Maximally Effective Region, or MER.

In simple terms, the MER refers to the region of the multipolar field where the field geometry appeared most biologically active in those laboratory experiments.

The MER was associated with the region near the interpole boundary, not simply the strongest Z-axis Gauss reading over a pole centre.

This is why the Gaussmeter images are so important:

• The Z-axis reading at the interpole boundary may be close to zero because the perpendicular field components cancel.
• The XY-axis reading at that same region may be strong because the field is running laterally between adjacent poles.
• The field gradient is greatest where the field changes direction rapidly across the surface.

A zero reading on one axis can therefore be misleading unless you understand what the instrument is measuring.

The interpole boundary is not a dead zone. It is where the geometry of the multipolar field becomes most important.

Proposed biological relevance

The proposed mechanism is that steep localized field gradients may influence membrane excitability and ion movement, including sodium and calcium ion dynamics involved in nerve signalling.

This should be stated carefully. The evidence does not justify saying that magnets simply “block nerves” or “switch off pain”. A more accurate description is:

localized static magnetic field gradients may influence the excitability of sensitized nerves under certain exposure conditions.

A more accurate practical formula

A useful way to think about Q Magnets is:

(Field Strength + Magnet Size) x Field Gradient = Useful Tissue Exposure

Field strength and magnet size influence how much of the field reaches the target depth.

Field gradient influences whether the field at that location has meaningful spatial variation.

Placement determines whether the region of useful exposure is positioned over the target tissue.

This is why Gauss matters, but field geometry matters more.

Part 9: The “45,000 Gauss” Marketing Problem

Once you understand Gauss as a point measurement, one of the most misleading practices in magnetic therapy marketing becomes obvious: additive Gauss ratings.

Here is how it works.

A magnetic mattress underlay, brace, or pad contains many small magnets. Each magnet might be rated at 450 Gauss at the surface. If the product contains 100 magnets, the marketing material may announce:

45,000 Gauss total magnetic power!

The arithmetic is simple:

450 G x 100 magnets = 45,000 G

But the physics is wrong.

Gauss is a field measurement at a point in space. You cannot add together the Gauss ratings of many separate magnets and claim the user is exposed to one combined 45,000 G field.

You cannot add the temperature of 100 cups of warm water and claim the result is boiling water a hundred times over. Each cup still has its own temperature. Likewise, each separate magnet has its own local field.

A person lying on such a pad is exposed to many small local magnetic fields, not one consolidated field equal to the sum of all the labels.

This matters because consumers may compare “45,000 Gauss” to a Q Magnet rated around 3,000 G at the surface and wrongly assume the mattress pad is much stronger.

In reality, each individual magnet in the pad may be weak, shallow, bipolar, and lacking the localized gradient structure that distinguishes multipolar medical magnets.

What to look for instead

Rather than asking for a total Gauss number, ask:

• What is the field strength per magnet at the surface?
• How quickly does the field fall with distance?
• What is the polarity configuration?
• Does it create a useful field gradient?
• Has the field been mapped?
• Where is the target tissue relative to the magnet?

Those questions are much more meaningful than additive Gauss marketing.

Part 10: Reading Gauss Numbers on a Multipolar Magnet – The Probe Orientation Problem

If you use a Gaussmeter to measure a Q Magnet, you will notice something that a simple product specification cannot fully explain.

The reading changes depending on:

• where the probe is placed
• which pole it is over
• whether it is over a pole centre or boundary
• whether the probe measures the Z-axis or XY-axis
• how far the probe is from the magnet surface

This is not a defect. It is the expected behaviour of a multipolar field.

What happens on a simple bipolar magnet?

On a typical bipolar magnet, one face is  North and the opposite face is South. If you measure across the same face, the values hardly vary, except near the edges, but the readings are generally similar in sign and pattern.

The field is comparatively uniform across that face.

This makes it easier to quote a single surface Gauss number, although even then the number depends on the exact probe position and distance.

What happens on a quadrapolar magnet?

A quadrapolar magnet has four alternating poles on one treatment face. A magnet viewer reveals the boundary lines between poles, often appearing as a crosshair pattern.

When you place a Gaussmeter probe over the surface:

• over a North pole centre, the Z-axis reading may be strongly positive
• over a South pole centre, the Z-axis reading may be strongly negative
• at the interpole boundary, the Z-axis reading may be near zero
• at the same boundary, the XY-axis reading may be strong

This is because the magnetic field is a vector. It has both magnitude and direction.

Strictly speaking, Gauss is the unit. The magnetic field itself is the vector.

A single Gauss number cannot fully describe a multipolar field because it does not tell you where the measurement was taken or which component of the field was measured.

Why MER belongs in this discussion

The interpole boundary is easy to misunderstand.

If you only measure the Z-axis, the boundary may appear unimportant because the perpendicular component reads close to zero. But when measured across the surface, the XY-axis field can be strong at that same location.

This is exactly why the MER concept matters.

The MER is not simply the point with the highest Gauss reading. It is a region where field direction, field strength, and field gradient combine in a way that may be more biologically relevant.

The Z-axis zero reading helps reveal the transition between adjacent poles.

The XY-axis reading helps reveal the lateral field component associated with that transition.

Together, they show why multipolar magnets cannot be evaluated by one maximum Gauss number alone.

Part 11: How Much Gauss Do You Actually Need?

This is the question most people really want answered.

The honest answer is not “the strongest magnet possible.” See also: is bigger or stronger always better?

A better answer is:

enough useful tissue exposure, in the right field geometry, at the right depth, for the right duration, placed over the right target.

Minimum threshold

Research suggests there is likely a lower threshold below which static magnetic fields produce little or no measurable biological effect in the models studied.

Importantly, this refers to the field at the target tissue, not merely the field at the magnet surface.

A 3,000 G surface reading does not mean the target tissue 20 mm below the skin is receiving 3,000 G.

Distance, not body tissue itself, is the main issue

Most body tissues are not strongly magnetic, so the main practical factor is distance from the magnet rather than the tissue “blocking” the field. The important question is how much field remains at the depth of the target structure.

This is why magnet size and placement matter.

Upper range and non-linear response

The Morris and Skalak studies suggest that stronger fields do not necessarily produce stronger biological effects. In their edema model, moderate fields produced measurable effects while a stronger field did not.

This does not prove one universal upper limit for every condition. It does show why “more Gauss” is not a complete strategy.

Target depth matters

A superficial nerve, tendon, or skin-level target may not require the same device as a deep spinal nerve, hip joint, or thick muscle region.

This is why Q Magnets are not one-size-fits-all. The correct device depends on the intended target and the depth of penetration required.

Gradient matters as much as strength

A lower surface Gauss multipolar magnet with a steep localized gradient may be more relevant for nerve modulation than a higher surface Gauss bipolar magnet with a more uniform field.

Strength without gradient is like a loudspeaker with plenty of power but no signal.

Better questions than “How many Gauss?”

Instead of asking only “How many Gauss?”, ask:

• Does the magnet generate localized field gradients?
• Is it multipolar or simple bipolar?
• Does the field reach the target tissue depth?
• Is the magnet large enough to cover the relevant structure?
• Is the MER or useful gradient region positioned over the target?
• Is the exposure duration appropriate?
• Is the timing appropriate for the condition or injury?

These are the questions Field | Dose | Placement is designed to answer.

Part 12: Safety – How Much Is Too Much?

Because neodymium magnets can have high material ratings, and MRI scanners operate at much higher field strengths, it is reasonable to ask whether these fields are safe.

The first distinction is that static magnetic fields are not ionising radiation. They do not carry the same type of energy as X-rays or gamma rays and are not known to damage DNA through ionisation.

However, that does not mean all magnetic field exposure is treated the same in safety guidance. Exposure limits depend on field strength, duration, body region, whether the field is static or time-varying, and whether the setting is controlled, occupational, medical, or general public.

MRI exposure is a controlled medical setting. Therapeutic magnets are local consumer or practitioner-applied devices. They are not the same exposure scenario. For a clearer comparison, read about MRI and magnetic therapy.

Q Magnets are local static magnetic devices. The N45 material rating of the magnetic alloy is not the same as whole-body exposure. The actual field varies by device model, surface point, distance, and orientation.

Q Magnets are registered with the Australian Therapeutic Goods Administration as a Class I Medical Device (ARTG 132324).

Standard contraindications

Do not use Q Magnets near:

• pacemakers
• implanted defibrillators
• implanted dorsal column stimulators
• infusion pumps
• magnetically programmable medical devices
• any implanted device that may be affected by magnetic fields

Do not use during pregnancy unless advised by a qualified healthcare professional, because insufficient testing data exists for that population.

Always consult a healthcare professional if uncertain whether contraindications apply.

This information is educational and does not replace medical advice. For a broader overview, visit the magnetic therapy resources page.

Part 13: Magnetic Terms Decoded – A Practical Glossary

Gauss (G)

A unit of magnetic flux density in the CGS system. One Gauss equals 0.0001 Tesla. In practical terms, Gauss describes magnetic field strength at a point and in a specific direction.

Tesla (T)

The SI unit of magnetic flux density. One Tesla equals 10,000 Gauss. Tesla is used more often in scientific literature, MRI specifications, and formal physics contexts.

Magnetic flux density (B)

The concentration of magnetic flux at a point. This is what Gauss and Tesla measure. B is a vector quantity, meaning it has both magnitude and direction.

Magnetic field intensity (H)

The applied magnetic field from a source, independent of the surrounding material. Measured in amperes per metre (A/m) in SI or Oersteds (Oe) in CGS. More relevant to engineering and materials science than consumer product descriptions.

Remanence (Br)

The residual flux density of a magnetic material after the magnetising field is removed. For N45 neodymium, this is typically around 13,200-13,700 G. This is often what manufacturers refer to when quoting the material Gauss rating.

Maximum Energy Product (BHmax)

A measure of magnetic energy stored per unit volume in a permanent magnet. It is the basis of N-grade designations such as N35, N45, and N52.

Coercivity (Hc)

The resistance of a magnetic material to demagnetisation. Neodymium magnets have high coercivity and maintain magnetisation under normal use.

Magnetic field gradient (dB/dx)

The rate at which magnetic flux density changes over distance. In multipolar magnets, steep localized gradients are created where adjacent opposite poles sit close together.

Interpole boundary

The region between adjacent North and South poles on a multipolar magnet. This is where the field changes direction rapidly and where the gradient may be steepest.

XY-axis measurement

A measurement of the magnetic field component running parallel to the magnet face. On a quadrapolar magnet, this can be strongest near the interpole boundary.

Z-axis measurement

A measurement of the magnetic field component perpendicular to the magnet face. On a quadrapolar magnet, this is usually strongest over pole centres and may read near zero at the interpole boundary.

Maximally Effective Region (MER)

A term from the McLean/Vanderbilt static magnetic field research describing a region of the quadrupolar field associated with stronger biological effects in cultured neuron experiments. It is not simply the highest Gauss point; it relates to field geometry, field direction, and gradient.

Penetration depth

How far the field maintains a potentially relevant strength into tissue. This depends mainly on magnet size, thickness, strength, geometry, and distance from the target.

Therapeutic window

The range of exposure conditions within which beneficial effects have been observed in particular studies or models. It does not imply one universal number for every condition.

Additive Gauss

A misleading marketing practice where the Gauss ratings of many separate magnets are added together. Gauss is a point measurement and cannot be summed across separate magnets in that way.

Final Summary: What Gauss Really Tells You

Gauss is a unit of magnetic flux density. It tells you the strength of a magnetic field at a specific point and in a specific direction.

One Tesla equals 10,000 Gauss.

For therapeutic magnets, a Gauss number may refer to several different things:

• the material remanence of the neodymium alloy
• a surface measurement at a pole centre
• a measurement at an interpole boundary
• a measurement along the Z-axis
• a measurement along the XY-axis

All of these can be legitimate measurements, but they are not interchangeable.

This is especially important for quadrapolar and other multipolar magnets. A simple bipolar magnet may give similar readings across the same face because the field is relatively uniform. A multipolar magnet can give very different readings over a few millimetres because the field is changing direction between adjacent poles.

That variation is the field gradient.

And in the science of multipolar medical magnets, field gradient is one of the most important variables.

The key lesson is:

Gauss matters, but it is only one part of the story.

A more complete understanding includes:

• field strength
• field direction
• field gradient
• magnet size
• distance from target tissue
• polarity configuration
• MER positioning
• exposure duration
• placement accuracy

So when someone asks, “What is the Gauss of a Q Magnet?”, the most accurate answer is:

It depends where and how you measure it.

And the more useful question is:

What useful tissue exposure does the magnet create when Field, Dose, and Placement are matched to the target?

That is why Q Magnets are designed as precision multipolar medical magnets, not simply high-Gauss magnetic products. You can compare device options in the Q Magnets shop.

References

Morris, et al. (2008) Acute Exposure to a Moderate Strength Static Magnetic Field Reduces Edema Formation In Rats. Am J Physiol Heart Circ Physiol: 2008 Jan;294(1):H50-7. PMID: 17982018; doi.

Morris, et al (2007). Chronic static magnetic field exposure alters microvessel enlargement resulting from surgical intervention. J Appl Physiol : 2007 Aug;103(2):629-36. PMID17478604; doi:10.1152/japplphysiol.01133.2006

McLean, M. J., R. R. Holcomb, et al. (1991). “Effects of Steady Magnetic Fields on Action Potentials of Sensory Neurons in Vitro.” Environmentalist 8(2). http://www.qmagnets.com/downloads/pub-effect-1.pdf

McLean, M., S. Engstrom, et al. (2001). “Static Magnetic Fields for the Treatment of Pain.” Epilepsy & Behavior 2(3): S74-S80 doi:10.1006/ebeh.2001.0211

Zablotskii, V et al, (2018). Cells in the Non-Uniform Magnetic World: How Cells Respond to High-Gradient Magnetic Fields. Bioessays. 2018 Aug;40(8). PMID: 29938810. doi

Colbert, A. P., H. Wahbeh, et al. (2009). “Static magnetic field therapy: a critical review of treatment parameters.” Evid Based Complement Alternat Med 6(2): 133-139. PMID 18955243; doi:10.1093/ecam/nem131

Medical disclaimer

Q Magnets are registered with the Australian Therapeutic Goods Administration as a Class I Medical Device (ARTG 132324). This article is educational in nature and does not constitute medical advice. If you are experiencing pain or a medical condition, consult your healthcare professional. Individual results may vary.