How to Compare EMF From 10 Everyday Household Devices

October 28, 2026

The honest version of this story is a method, not a leaderboard. We are not publishing a ten-device results table, because a comparison is only as good as the documentation behind each row, and a single unverified number per device would be worse than none. What this post gives you is the protocol that would make such a table meaningful: the right instrument for each field type, fixed positions, realistic operating modes, and repeats. Run it on the ten devices below, and you will have a comparison you can actually trust, in your home, on your equipment.

The Lineup

Ten candidates, chosen because they cover the field types a household actually contains. These are categories, not a shopping list: the exact model and operating mode of each device in your home is what the protocol documents, and results rows would carry that documentation before any number is published.

1. A smart TV
2. An induction cooktop
3. A Wi-Fi router
4. A laptop
5. A wireless charging pad
6. A corded phone or laptop charger
7. An LED lamp with a dimmer
8. A hair dryer
9. A microwave oven
10. A Bluetooth speaker

Notice what the list spans: RF sources (the TV, router, and speaker), high-current power-frequency sources (the hair dryer, the cooktop), switching and conducted-noise sources (the dimmer, the chargers), and a time-varying magnetic source (the induction cooktop and the wireless charger). That spread is the point. A comparison that only looked at one field type would describe a fraction of the house.

The Protocol Matrix

Each device gets a row with the instrument and band that match its field type, a baseline, fixed positions, a realistic mode, and a repeat count. The U.S. National Institute of Environmental Health Sciences’ guide to electric power EMF is a useful reference for the power-frequency side of this table.

Device	Field type(s)	Instrument and band	Fixed positions	Realistic mode
Smart TV	RF; power-frequency near the cord	RF meter covering the Wi-Fi and Bluetooth bands; 60 Hz magnetic	Seating position; 30 cm from the set	Streaming a fixed program; idle
Induction cooktop	Time-varying magnetic field at the surface	60 Hz or appropriate-band magnetic meter	10 cm above the surface; standing position	Compatible cookware, normal cooking operation
Wi-Fi router	RF	RF meter covering the router’s bands	1 m from the unit; the nearest occupied point	Idle; a fixed transfer
Laptop	RF when radios are on; power-frequency while charging	RF meter; 60 Hz magnetic	On the lap or desk, in use position	On battery; plugged in and charging
Wireless charger	Magnetic field with a receiver present	60 Hz or appropriate-band magnetic meter	10 cm from the pad; pocket position	Actively charging a phone
Corded charger	Power-frequency and switching-related fields near the adapter	60 Hz magnetic; conducted-noise instrument if available	10 cm from the adapter; outlet position	Charging; idle on the wall
LED lamp with dimmer	Conducted noise on the circuit; power-frequency	Conducted-noise instrument; 60 Hz magnetic	At the outlet; at the lamp	Dimmed; full brightness; off
Hair dryer	Power-frequency magnetic field (high current)	60 Hz magnetic meter	1 m from the device in use; at the outlet	In normal use
Microwave oven	RF, including certified leakage	Trained testing with the appropriate instrument and procedure	Door position per the procedure	Running per the procedure
Bluetooth speaker	RF during playback	RF meter covering the Bluetooth band	1 m from the speaker; listening position	Playing audio; idle

Three rules hold for every row. Operate all equipment normally, the way you would actually use it. Record the duty cycle where it applies, because a device that transmits or draws current only part of the time is a different exposure than one that runs continuously. And take the baseline first, with the device off or unplugged, so each row has its own background.

Two instrument notes apply across the whole matrix. First, know what your meter reports: peak, average, and time average are different numbers for the same source, and a bursty signal, like a router or a dimmer, can look very different depending on which one you record. Note the mode on every row, and keep it the same across the comparison. Second, check the instrument’s range against the device: a meter that does not cover the band a device uses cannot see it, and a low reading from an instrument that is out of range is not a low field. For interpreting whatever numbers you get, our guide to high meter readings covers the common surprises, and the home inspection case study shows how the same logic scales to a whole house.

The Worksheet

This is the blank worksheet in protocol mode. Fill one row per device, per position, per mode. The columns exist because a number without its conditions is not a result:

Device and model	Setting / mode	Position and distance	Background	Reading	Units	Time window	Repeats	Uncertainty / notes

Two conventions keep the worksheet honest. First, below detection is not zero: if the instrument does not register a signal above its threshold, write “below detection” with the conditions, not 0. Second, no cross-field leaderboard: RF in mW/m² and magnetic flux density in µT or mG are different quantities, so the finished comparison is a set of tables, one per field type, with compatible metrics inside each. And no extrapolation: one device of one model tells you about that device, not about a brand or a category.

How to Read the Comparison

When the worksheet is full, read it the way it was built to be read. Within each field type, compare devices at the positions where you actually use them, not at an arbitrary distance: the cooktop at the standing position, the router at the bed, the speaker at the listening chair. A number at 10 cm from a device is a property of the device’s surface, and it is not the number your body spends time near. The background column tells you whether a device is adding anything at all to the room, and the mode column tells you whether the difference you see is the device working or the device idling.

Three things the comparison will not do, on purpose. It will not rank devices across field types, because mW/m² and µT are not the same quantity. It will not generalize from your one device to a brand or a category, because one sample of one model is one sample. And it will not attach a health interpretation to any number, because the table describes fields, and fields are not outcomes. What it will do is tell you, device by device and position by position, where the real contributions in your home are, which is exactly the information the next section acts on.

What You Can Change, and Recheck

The comparison is only half the value; the other half is the decision it supports. For most of these devices, the levers are the same three: distance from the use position, the operating mode, and where the device or its power hardware sits. Move the router off the nightstand, run the cooktop comparison at the standing position rather than the surface, keep the wireless charger out of the pocket you carry a phone in. Then recheck the same fixed positions, because the point of the worksheet is that you can verify the change instead of assuming it.