If you've ever tried to read up on EMF and felt like you needed a translator, you're not alone. Milligauss, volts per meter, SAR — the units pile up fast. Let's cut through the jargon so the numbers actually mean something.
Milligauss (mG) — for ELF Magnetic Fields
Milligauss measures extremely low-frequency magnetic fields — the kind coming from power lines, wiring, and appliances. A typical home sits around 0.5–2 mG in the background. Stand right next to a running refrigerator and you might see 5–50 mG. Directly under high-voltage lines can read 50–200 mG or more.
Quick reference points:
- Typical home background: 0.5–2 mG
- Near a running appliance: 5–50 mG
- Under high-voltage lines: 50–200+ mG
Volts per Meter (V/m) — for Electric Fields and RF
Volts per meter covers both the electric fields from your home's wiring and the strength of radiofrequency signals. A WiFi router a few feet away might register 0.1–1 V/m, while a cell phone held to your head can produce fields of several V/m.
Specific Absorption Rate (SAR) — for Devices Near the Body
SAR measures how much RF energy your body absorbs from a wireless device, expressed in watts per kilogram (W/kg). In the US, the FCC caps cell phone SAR at 1.6 W/kg averaged over 1 gram of tissue, and manufacturers publish each phone's rating.
One important caveat: SAR is measured under worst-case, maximum-power conditions. Real-world exposure is usually lower — but it's also variable. A phone struggling with a weak signal ramps up its power and can exceed its rated SAR in everyday use.
What Numbers Should I Actually Care About?
There's no single universally agreed "safe" threshold, and you won't find one on this site. But many cautious researchers suggest aiming for long-term ELF exposure below 1 mG, especially where you sleep, and minimizing RF where it's practical to do so.
The mindset that actually helps: don't chase a perfect number. Measure, compare, and reduce what you reasonably can. A basic meter turns a fuzzy worry into a clear picture — and once you can see your sources, the fixes become obvious.
