EMF Units Explained: V/m, milliGauss, µW/m² Etc. (Beginners) | emfcaution.com (2024)

Welcome to the world of weird names and confusing units. The physics behind EMF radiation can easily get to your head when you are new to this stuff. But stick with me for a few minutes here and everything should start clearing up!

In this article, I will explain to you exactly how we measure EMF radiation.
We will do this from a beginners level in plain English!

Let’s get started!

Table of Contents

It’s really important to understand these different measuring units because they can get really confusing when you are trying to compare two different numbers.

What Are The Standard Units For Measuring EMF Radiation?

EMF Units Explained: V/m, milliGauss, µW/m² Etc. (Beginners) | emfcaution.com (1)

The problem with measuring EMF radiation is that we haven’t defined any standards yet. Some EMF meters will use one set of units while the next will measure the same things with a completely new set of units.

Hopefully, this article will help you get clarity and understand the basic units we use and how to convert from one to the other.

Before we dive into the units we need to make sure we know the three most “popular” types of EMF:

  1. RF radiation
    RF stands for “Radio Frequencies” and this is the type of radiation we find around wifi, smartphones, laptops, tablets, cell towers, Bluetooth, and much more. You can check out our beginner’s guide to RF radiation here.
  2. Magnetic fields (ELF radiation)
    Magnetic fields are different. They are closely related to the electric fields we look at below. Magnetic and electric fields always appear together and they are always there (at some level) when we have electricity. They form around electric cords, power lines, generators, chargers for electric devices, etc.
    Magnetic fields and electric fields are what we call ELF radiation. ELF stands for “Extremely Low Frequencies” and we have a great guide to ELF here for beginners.
  3. Electric fields (ELF radiation)
    As I mentioned above, electric fields appear around electricity and always together with magnetic fields. One thing we need to remember about electric fields is that they are present as soon as something is connected to a power cord. Also when the power isn’t turned on! You can learn the basics about magnetic fields and electric fields here.

Now you should know that we are dealing with three different types of EMF radiation. That’s important to understand before we can proceed to take a look at how we measure the level of each type of radiation.

Here are the different ways we measure each type of EMF:

EMF TypeMeasuring Units
RF radiationVolts per meter (V/m), microWatts per square meter (µW/m²)
Magnetic FieldsmilliGauss (mG), nanoTesla (nT), Ampere per meter (A/m)
Electric FieldsVolts per meter (V/m),

Note: I have bolded the units we use on this website. These are also the most commonly used units in the United States. At least among amateurs and people who are new to EMF radiation.

Let’s take them one by one to break it down.

1) Measuring Units For RF Radiation

Remember that RF radiation is wifi signals and Bluetooth signals. These wireless technologies impact our cells by heating them up a little bit (thermal radiation effect) and they also impact us on a biological level.

RF radiation always has a frequency. This is also why you have to set your old radio to a certain frequency (FM or AM) in order to pick up a signal. However, when we measure the strength of the radiation we don’t look at the frequency. Instead, we are more concerned with how much the radiation impacts the surface it “touches”.

When the RF radiation causes an electric current on the surface it reaches.

This is also why people who are hypersensitive to electromagnetic radiation can literally feel the radiation. My wife explains it like a buzzing sensation on the skin.

Volts per meter (V/M) explained

The easiest way to measure and understand RF radiation is to stick to volts per meter (V/m). It’s typically easier to understand than microWatts per square meter (µW/m²).

In all our examples on this website, I also stick to V/m when I talk about RF radiation. This just keeps things easier to understand and work with. I like this measuring unit as it is easier to explain and understand than the other alternatives. At least if you ask me. If you have a degree in physics or engineering you might prefer to use µW/m² but for the rest of us, I think we should at least start with V/m.

When we talk about V/m we are looking at how intense the electromagnetic fields is that is created by the radio frequency.

When we measure an RV signal of 1 V/m we are dealing with a signal where there’s 1 Volt difference between two points that are 1 meter apart.

MicroWatts per square meter (µW/m²) explained

We can also measure the strength of our RF radiation with µW/m²

Instead of microWatts per square meter (µW/m²), we could just as well use W/m2 but we would get REALLY low numbers.

1 W/m² = 1000,000 µW/m²
1 μW/cm² = 10,000 μW/m²
(We can also use cm² instead or m².)

But these are all the same thing.

We are measuring the effect in Watt on a specific surface area (m² / cm²). instead of looking at the difference in Volts between two points we are measuring what we call the “power flux density”.

This basically means that we measure the power of the radiation as an average over time.

For that reason, we also prefer V/m where we can get better readings on RF radiation that may spike all of a sudden. This is very typical for Bluetooth and Wifi signals. Our smart meters, phones, laptops, routers, etc. will typically send outbursts of radiations all of a sudden and they go back to a lower intensity.

We will leave the µW/m² unit for now and stick to V/m.

But now you know that you can also measure RF radiation with µW/m² and you also know that it’s a little more complicated to use than V/m.

2) Measuring Units For Magnetic Field Radiation

EMF Units Explained: V/m, milliGauss, µW/m² Etc. (Beginners) | emfcaution.com (2)

In the United States, we typically use Gauss (or milliGauss – mG) to measure magnetic fields. In other parts of the world, people often prefer Tesla (or nanoTesla nT).

Both types of units measure the exact same thing.

It’s easy to convert between the two. You simply multiply your mG value by 100X to convert it to nT:

1mG = 100nT
(1 Gauss = 1/10,000 Tesla)

We are measuring the strength of the magnetic fields which is generated by current flow. This basically means that when an electronic device is coupled to your grid with an electrical cord there will be current flowing. This creates magnetic fields.

What Is Gauss?

Gauss is named after the German mathematician and physicist Carl Friedrich Gauss. Gauss is used whenever we need to measure the strength of a magnet (the magnetic fields around a magnet).

If you can allow me to get a little technical for a second, one gauss is the same as one newton per ampere meter.

But don’t worry about it if this is all nonsense to you. You don’t have to understand the physics and the mathematics behind Gauss and Tesla units in order to understand and measure your EMF levels.

We can also measure magnetic fields using other measuring units such as Oersted (OE) and Maxwell. But these units are typically not used with EMF meters or among people who are concerned with EMF radiation.

One gauss unit is the same as 1 maxwell per cm², in case you ever need to calculate forth and back between the two.

3) Measuring Units For Electric Field Radiation

For electric fields, we can also use the V/m measuring unit. This is the most used unit here.

We already explained this unit above. It’s pretty easy to work with and it’s also built into the EMF meter we recommend. Let’s look at the EMF meter.

What Are Safe Levels Of EMF Radiation?

Now you should have a good understanding off the different ways we measure EMF. That’s an important start in order to protect yourself and your family.

Let’s take a closer look at what the recommended (maximum) EMF levels and limits are.

We have 3 different sets of values:

  1. Daytime
    It’s during the day we have the most radiation going on around us. The limits below should be possible to reach when you take clever precautions.
  2. Nighttime
    We can go for lower limits at night because we don’t need our electronic devices turned on.
  3. EHS
    EHS stands for “Electro-HyperSensitivity”. These are people who are very sensitive to electromagnetic fields. My wife is among this group of people and she is definitely sensitive to this stuff. This is also what got us into EMFs in the first place. This group of people needs much lower limits than the rest of us. They are typically able to detect RF and ELF radiation on their skin etc. There are different degrees off how’s sensitive people are (it’s not that you are hypersensitive or not).
    Note: Here’s our list of common symptoms among people with electro-hypersensitivity. When you run over this list you will get a quick feel of whether this is something you are struggling with or not.

According to building biologists, these are the recommended levels of EMF in our houses:

EMF typeDaytime limitsNighttime limitsLimits for EHS people
RF Radiation0.2 V/m0.06 V/m0.02 V/m
Magnetic Fields (ELF)1 mG1 mG0.1 mG
Electric Fields (ELF)10 V/m1.5 V/m0.3 V/m

As you can see, we want much lower levels of radiation at night.

Now that you know the difference between V/m and milliGauss these charts should make much more sense to you. It’s still not easy to understand exactly what’s going on behind these expressions on a physical level. I must say that I also struggle sometimes when I’m trying to understand all of these numbers.

It’s not always easy to wrap your head around milliGauss, microTesla, and Ampere/m. Sometimes you will mix things up.

This is also the reason why we recommend the specific EMF meter below. It has a nice and very user-friendly interface on the right side of the screen. It will show you if you are in the green stone, the yellow zone, or in the red zone when you are testing the levels. But we will get back to that.

The EMF Meter We Use

When I first started to learn about EMF radiation I quickly realized that I needed an EMF meter. It’s simply impossible to know where you have (too) high levels of radiation in your home and around you without the EMF meter.

There are many different brands and models on the market.

I started by looking at which models building biologist and other experts were using in their videos and examples. I quickly found out that the Cornet EMF meter is one of the most user-friendly and affordable EMF meters on the market.

Here’s what it looks like.

This is me holding the EMF meter outside our front door. As you can see I am measuring a pretty high level of RF radiation because we have a cell tower across the street.

EMF Units Explained: V/m, milliGauss, µW/m² Etc. (Beginners) | emfcaution.com (3)

You can read more about this EMF meter here where we also have a link to it at Amazon.

The EMF meter above is great because it can measure all the three types of EMFs we are concerned with. It has 3 built-in sensors on the back in order to measure:

  1. RF radiation
  2. Magnetic fields (ELF)
  3. Electric fields (ELF)

When you have these three types of EMF radiation types covered you are good to go.

This Meter Is Great If You Struggle With The Measuring Units

As I mentioned above, it’s easy to mix up the different measuring units. This is because we are dealing with different types of EMF radiation and we are also dealing with more than one ways to measure the radiation of the same type.

This is where this specific EMF meter is really brilliant!

As you can see from the picture above, there’s a scale mounted on the far right side of the screen. It will show you immediately if you are in the green zone, the yellow zone, or in the red zone.

This range is calibrated according to the recommendations among building biologists.

Luckily, building biologists are agreeing on these limits. They might be using different measuring units, but they are able to convert between the two and still talk about the same limit.

This is why you can always see an indication of whether you are measuring high toxic levels or if the radiation you are measuring is within the recommended limits. This makes everything so much easier because you don’t have to think about the many different measuring units.

Do I Really Need An EMF Meter?

The short answer is yes.

There’s simply no other ways to know how much radiation you have in your home.

It is possible to find information online where people have tested different types of electronic devices and appliances, but you need to do your own testing. This is because each brand and model of an electronic device will emit its own level of radiation. Two routers from the same brand can emit totally different RF radiation values.

We have also done a ton of testing with our EMF meter and if you want to see some of the numbers from our house you can check out these two articles:

  1. EMF values for 19 home alliances
  2. EMF values for 45 electronic devices in our homes

(Just remember, these are readings from our house and your induction cooktop or your router will probably not emit the same amount of radiation as ours).

How To Convert V/m to W/m²

We can convert one to the other.

Here’s how you go from V/m to W/m²:

V/m = (W/m2x 377)1/2

So, let’s say you want to convert 1 mW/m² to V/m. You will have to do this:

(0.001 x 377)1/2 = 0.6 V/m

Well, now we are getting very technical.


EMF Units Explained: V/m, milliGauss, µW/m² Etc. (Beginners) | emfcaution.com (2024)


What is EMF for dummies? ›

EMF is short for electromagnetic fields or sometimes known as electromagnetic radiation (EMR) or electromagnetic energy (EME). Electromagnetic fields are present everywhere in our environment – the earth, sun and ionosphere are all natural sources of EMF.

What level of EMF is unsafe? ›

In our opinion, based on our experience, knowledge and further search on the web, the safe levels for High Frequency is up to 70 mv/m meter, for Low-Frequency EMF magnetic fields, it can go up to 0.7 Milligauss and for the low-frequency electric field, it should be less than 6 V/m (volts per meter).

What are the units for EMF? ›

Despite its name, electromotive force is not actually a force. It is commonly measured in units of volts, equivalent in the metre–kilogram–second system to one joule per coulomb of electric charge.

Is 3 milligauss safe? ›

range from 0.1 to 4 mG. EMF levels above this range are not necessarily hazardous, but indi- cate EMF levels above what's typical background inside a home. Deciding where to live rests upon different considerations for each individual.

What is the simple explanation of EMF? ›

What Is Electromotive Force? Electromotive force is defined as the electric potential produced by either an electrochemical cell or by changing the magnetic field. EMF is the commonly used acronym for electromotive force. A generator or a battery is used for the conversion of energy from one form to another.

What is the three finger rule in physics? ›

Fleming's Left Hand Rule states that if we arrange our thumb, forefinger and middle finger of the left hand perpendicular to each other, then the thumb points towards the direction of the magnetic force, the forefinger points towards the direction of the magnetic field and the middle finger points towards the direction ...

What emits the most EMF? ›

Functioning electrical appliances and power lines produce EMF. Even the earth produces small amounts of EMF. Therefore, everyone is exposed to this form of energy. The highest EMF exposure can occur using appliances such as electric blankets, microwave ovens, and hair dryers.

What is a normal Milligauss reading? ›

mG is “milligauss” and uT is “microtesla.” Measured using a gaussmeter or teslameter. What is a typical AC magnetic field level in a home? Inside a house usually measures about 0.2 to 1.0 mG if not very close to appliances or wiring. Apartments and condos are a bit higher.

What does EMF do to your brain? ›

Neurological cognitive disorders, such as headache, tremor, dizziness, loss of memory, loss of concentration and sleep disturbance due to RF-EMF have also been reported by several epidemiological studies (Kolodynski and Kolodynska, 1996; Santini et al., 2002; Hutter et al., 2006; Abdel-Rassoul et al., 2007).

Can a cell phone detect emf? ›

But fortunately, today most smartphones and iPhones have inbuilt sensors that can be used for emf detection. So for it, software engineers develop multiple applications to detect emf radiations using device sensors.

What's the difference between emf and voltage? ›

Emf is the voltage developed between two terminals of a battery or source, in the absence of electric current. Voltage is the potential difference developed between the two electrode potentials of a battery under any conditions.

What is the symbol for emf? ›

Electromotive force (EMF) is equal to the terminal potential difference when no current flows. EMF and terminal potential difference (V) are both measured in volts; however, they are not the same thing. EMF (ϵ) is the amount of energy (E) provided by the battery to each coulomb of charge (Q) passing through.

What is a safe level of EMF? ›

Thus, any reading higher than 0.5 mG is above the "usual" ambient exposure. Many experts and public officials, as well as the few governments that have made an effort to offer public protection, have adopted the 3 mG cutoff point.

How much mW/m2 is safe? ›

A realistic approach to those who want to limit their exposure to elevated (according to the proposed limits) wireless radiation values is to avoid places with values >100 microwatts / m2 during the day and places with values >10 microwatts / m2 in sleeping areas. What are high-frequency electromagnetic fields?

What is the average EMF level in a home? ›

Exposure levels vary from individual to individual and from home to home, but a study by the Electric Power Research Institute (EPRI) puts the background levels of power line magnetic fields in the typical U.S. home at between 0.5 mG and 4 mG with an average of 0.9 mG.

What is EMF in layman terms? ›

In electromagnetism and electronics, electromotive force (also electromotance, abbreviated emf, denoted ) is an energy transfer to an electric circuit per unit of electric charge, measured in volts. Devices called electrical transducers provide an emf by converting other forms of energy into electrical energy.

What is EMF explained for kids? ›

Electric and magnetic fields (EMF) are invisible lines of force that surround any electrical device. Power lines, electrical wiring, and electrical equipment all produce EMF.

What do EMF waves do to you? ›

The main effect of radiofrequency electromagnetic fields is heating of body tissues. There is no doubt that short-term exposure to very high levels of electromagnetic fields can be harmful to health.

How to block EMF radiation? ›

Consider using EMF shielding products such as EMF blocking curtains, blankets, smart meter covers, or faraday fabric to reduce your exposure to EMF radiation. These products are designed to absorb or deflect EMF radiation and can be used in areas where electronic devices are frequently used.

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