Measuring EMF at home

Last reviewed: 20 October 2026

Our calculator produces model-based estimates; a meter produces a spot reading of the field at one place and one moment. Both are useful, and they are not competitors: the calculator tells you which devices and distances dominate your exposure profile, and a home meter tells you what the field actually is at your bed, desk or kitchen counter. This guide covers what a home user can measure and with what: the meter categories, the units they read — µT, V/m and W/m² — and one complete worked reading. Every limit and measurement fact below carries a dated source, and readings are treated as indicative estimates, not compliance measurements.

Which meter measures what

No single cheap box covers the whole EMF spectrum. The guidelines themselves split it: power-frequency (ELF) fields are covered from 1 Hz to 100 kHz (ICNIRP, 2010), and radiofrequency (RF) fields from 100 kHz to 300 GHz (ICNIRP, 2020). Home meters are built for one of those ranges — an ELF gaussmeter will not respond to a gigahertz Wi-Fi signal, and an RF meter will not respond to the 50/60 Hz field around a fridge.

• ELF magnetic-field meters (gaussmeters), reading in µT or mG. These measure the magnetic fields produced by alternating current: household wiring, distribution panels, appliances with motors or transformers, power lines and substations. This is the meter for the power-frequency fields the ICNIRP (2010) guidelines cover. It cannot measure RF signals or electric fields.
• ELF electric-field meters, reading in V/m. These measure the 50/60 Hz electric fields near ungrounded devices, wiring and overhead lines; the public reference level at 50 Hz is 5 kV/m, far above typical indoor values (ICNIRP, 2010). They cannot measure magnetic fields or RF.
• RF (radiofrequency) meters, reading in µW/m² or V/m. These measure the power-density of radio signals: Wi-Fi routers, phones, Bluetooth devices, smart meters, broadcast transmitters and mobile towers — the 100 kHz–300 GHz range the ICNIRP (2020) guidelines cover. Check that the meter's specified frequency range covers the signals you care about: RF survey practice relies on calibrated instrumentation with a defined frequency response (IEEE, 2021). An RF meter cannot measure power-frequency magnetic fields.
• Combined meters. Some consumer instruments bundle an ELF gaussmeter and an RF detector in one box. They are a convenience, not a calibration: judge each function's specified range and accuracy separately, exactly as you would for the single-purpose instruments (IEEE, 2021).
• Phone apps are not meters. A phone's compass magnetometer exists to sense the orientation field, and phone apps carry no calibration or defined frequency response; proper field surveys use calibrated instruments (IEEE, 2021). Treat app readings as rough indicators at best.

The units: µT, V/m and W/m²

Each unit measures a different physical quantity, and each applies to different source types. This is also how our calculator's frequency bands are quoted — µT for the magnetic bands, W/m² for the radiofrequency ones.

• µT (microtesla) — magnetic flux density. The quantity for ELF and power-frequency magnetic fields: household wiring, appliances, power lines, substations and EV charging. The calculator quotes its Static, ELF, Power Frequency and Low Frequency bands in µT. Most of the world reports power-frequency magnetic fields in µT; North American studies and meters often use milligauss (mG) — WHO (2007) reports residential survey data in both, and 1 µT = 10 mG. Context for any reading: typical home backgrounds run about 0.01–0.3 µT (WHO, 2007), and the ICNIRP public reference level at power frequency is 200 µT (ICNIRP, 2010).
• V/m (volt per metre) — electric field strength. The quantity for electric fields, in two home contexts: the 50/60 Hz electric field from wiring, overhead lines and ungrounded appliances (ICNIRP's public reference level at 50 Hz is 5 kV/m; ICNIRP, 2010), and the field strength of RF signals. Between 400 MHz and 2 GHz the ICNIRP public reference level for E-field strength rises with frequency to 61 V/m (RMS) at 2 GHz; above 2 GHz the 2020 guidelines mark the E-field level not applicable and set the limit directly as 10 W/m² incident power density (ICNIRP, 2020). Our calculator quotes its bands in µT and W/m² rather than V/m; in far-field (plane-wave) conditions the two RF quantities are linked by power density = E²/377 — 10 W/m² corresponds to about 61 V/m — the relationship ICNIRP's field-strength reference levels assume (ICNIRP, 2020).
• W/m² (watt per square metre) — power density. The quantity for RF power flowing through a given area: Wi-Fi, phones, smart meters, cell towers and 5G. The calculator's Medium Frequency and Radio Frequency bands are quoted in W/m², against reference levels that rise with frequency — f/200 W/m² between 400 MHz and 2 GHz, and 10 W/m² from 2–300 GHz (ICNIRP, 2020). Consumer RF meters usually display microwatts per square metre (µW/m²); the SI prefixes do the conversion — 1 W/m² = 1,000,000 µW/m² (BIPM, 2019) — so a meter reading of 5,000 µW/m² is 0.005 W/m², three orders of magnitude below the 2–300 GHz public reference level of 10 W/m² (ICNIRP, 2020).

A worked example: one complete home reading

The numbers below are illustrative — the point is the procedure, and every contextual figure carries its source. The setup: a kitchen with an electric stove, measured with an ELF gaussmeter.

1. Pick the meter for the field. The stove's field is a power-frequency magnetic field, so the tool is a tri-axis ELF gaussmeter covering 50/60 Hz and reading in µT. (With a single-axis meter, rotate it through all three orientations and note the largest value.)
2. Record the background first. With the stove off, read at the kitchen doorway, about 2 m away: say the meter shows 0.06 µT. That sits inside the typical home background of about 0.01–0.3 µT (WHO, Environmental Health Criteria 238, 2007).
3. Take the source reading at a stated distance. Switch the oven and a hob ring on, and read where you actually stand — at torso height, 30 cm in front of the stove: say the meter now shows 3.2 µT at 0.3 m. Note the distance and the appliance state with every reading; appliance fields are only present while the appliance runs, and they fall off rapidly with distance (WHO, 2007).
4. Step back and read again. One metre away the meter shows, say, 0.3 µT — already back at the top of the typical background band (WHO, 2007). Doubling distance cuts the field of a compact source to roughly a quarter, which is why distance is the lever that changes the reading most (WHO, 2007; see Methodology for the fall-off law our calculator applies per source).
5. Compare against the dated limits. The 3.2 µT at 0.3 m is around ten times the top of the home background band (0.01–0.3 µT, WHO, 2007) and more than sixty times smaller than the ICNIRP public reference level of 200 µT at power frequency (ICNIRP, 2010). On this page's own terms that reading is a spot estimate of one place at one moment — not a long-term average, which is the quantity the epidemiology is framed around (IARC Monographs Vol. 80, 2002; WHO, 2007).
6. Model it in the calculator. The link below opens the calculator with the Electric Stove source pre-selected. It takes a stance band rather than an exact distance — the example's 0.3 m sits on the boundary between "Close (15–30 cm)" and "Standard (30–60 cm)", so try both — plus cooking sessions per day and their average minutes (say, 2 sessions of 20 minutes) and a heat setting. Its output is a time-weighted 24-hour average, not a while-cooking value, so average your meter reading the same way before comparing: 3.2 µT for 40 minutes a day is 3.2 × 40 ÷ 1,440 ≈ 0.09 µT as a daily average. If the two figures differ, that is expected — the calculator works from published emission ranges and a stance band, the meter from your actual appliance.

Open the calculator — Electric Stove

Where the limits come from, and which band each unit maps to, is on the standards and methodology reference page — the calculator's Power Frequency band (quoted in µT) is the one this worked example's reading belongs in.

What a home reading is — and is not

• A consumer-meter reading is a spot reading: the field at one point, at one moment, in one appliance state. It is an estimate in exactly the sense our homepage uses — it is not the measurement our limits discussion leans on, and it is not a compliance survey.
• The exposure quantities in the epidemiology are long-term averages over time (IARC Monographs Vol. 80, 2002), so a handful of spot readings cannot be turned into an average exposure without more structure.
• Meters also differ in accuracy and frequency coverage between models; survey-grade work relies on calibrated instrumentation with a defined response (IEEE, 2021).
• No adverse health effects are confirmed below international guideline limits, and research on long-term effects is ongoing (WHO, 2007). Measuring your home is a way to understand your environment — the same framing as the calculator's methodology, and no substitute for either source.

Sources

1. ICNIRP (2010), "Guidelines for limiting exposure to time-varying electric and magnetic fields (1 Hz to 100 kHz)", Health Physics 99(6): 818–836.
2. ICNIRP (2020), "Guidelines for limiting exposure to electromagnetic fields (100 kHz to 300 GHz)", Health Physics 118(5): 483–524.
3. WHO (2007), "Extremely low frequency fields", Environmental Health Criteria 238, World Health Organization, 2007.
4. IARC (2002), "Non-ionizing radiation, Part 1: static and extremely low-frequency (ELF) electric and magnetic fields", IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, Vol. 80.
5. IEEE (2021), "IEEE Recommended Practice for Measurements and Computations of Radio-Frequency Electromagnetic Fields With Respect to Human Exposure to Such Fields, 100 kHz–300 GHz", IEEE Std C95.3.1-2021.
6. BIPM (2019), "The International System of Units (SI)", 9th edition, Bureau International des Poids et Mesures — SI prefixes and the tesla.

Related guides

• Household appliance EMF exposure
• Power line EMF exposure
• WiFi router RF exposure
• Mobile phone RF exposure
• All per-source guides (on the homepage)