How to Measure Electromagnetic Fields (EMF) at Home

Electromagnetic fields consist of two main components:

• Electric field (E-field)
• Magnetic field (B-field)

To these we add radiofrequency radiation (RF) - such as Wi-Fi and mobile signals. These fields are measured separately because they differ in their physical nature and behaviour.

What equipment do you need?

The most commonly used device is a combined EMF meter, which measures:

• Magnetic field (µT or mG)
• Electric field (V/m)
• Radiofrequency radiation (RF)

Separate devices can also be used:

• Gaussmeter (for magnetic fields)
• E-field meter
• RF meter

For home measurements, a combined meter is usually the most practical option.

Step 1: Take a baseline measurement (background level)

Before looking for specific sources, start with a baseline measurement.

• Switch off: all appliances, the Wi-Fi router, televisions, computers
• Measure: in the centre of the room, next to the bed, next to your desk

📌 Write down the readings - this is your “clean background” level, which you will use for comparison.

Step 2: Measure the magnetic field (50 Hz)

Magnetic fields in the home usually come from electrical wiring and operating appliances.

Common sources: fridge, washing machine, fuse board, extension leads, walls containing electrical wiring

• Select µT mode (or mG)
• Hold the meter 5–50 cm from the source
• Move it slowly in different directions
• Record the maximum reading

📌 It is especially important to measure around the bed.

Step 3: Measure the electric field

Electric fields exist even when a device is plugged in but not switched on.

• Select V/m mode
• Measure near walls, cables, sockets and extension leads

Then switch off the circuit breaker for the room and measure again.

📌 If the readings drop significantly, the field is coming from the internal electrical wiring.

Step 4: Measure Wi-Fi and mobile frequencies (RF)

Select RF mode.

Measure: next to the router, 1 metre away from it, near the bed, in relaxation areas

For more realistic readings, stream a video while measuring.

📌 It’s also useful to measure in the evening, when mobile network traffic is often higher.

Important principles when measuring

• Keep the meter 5–50 cm from the source
• Move it slowly in different directions
• Record the maximum value
• Measure at around 1 metre height (for room assessment)
• Test at different distances (0.5 m, 1 m, 2–3 m)
• Measure during active use (e.g. video streaming)

Common measurement mistakes

❌ Measuring too close to the source
❌ Covering the sensor with your hand
❌ Ignoring background levels
❌ Comparing µT and mG without converting units

How to get more accurate results

✔ Measure in several locations
✔ Record both maximum and average readings
✔ Measure at different times of day
✔ Use a tri-axis meter

What matters most for a healthy environment

• Distance is the strongest factor.
• The bed should be an area with the lowest possible readings.
• The fuse board should not be close to where you sleep.
• The router is best placed in a room where you do not sleep.

Sometimes small changes - such as moving the bed or the router - are entirely sufficient.

Measuring electromagnetic fields gives you a clearer picture of your actual home environment. If you would like to understand the most common EMF sources in everyday life, you can also read our article: EMF at Home: 5 Common Sources.

Understanding comes step by step.

In the next article, we will look at how to interpret the readings you have measured.