# Milligauss (mG) and microtesla (µT)

> The two units for power-frequency magnetic fields: 1 µT = 10 mG, so 0.4 µT = 4 mG.

- Canonical URL: https://emfbase.com/glossary/milligauss
- Collection: Glossary
- Record id: `glossary:milligauss`
- Status: verified
- Last verified: 2026-08-12
- JSON: https://emfbase.com/api/glossary/milligauss

## Key values

- **Category:** measurement

## Definition

Milligauss belongs to the CGS system and is standard in North American consumer practice; microtesla is the SI unit and is used in European guidelines and scientific literature. The conversion is exact: 1 µT equals 10 mG. Most confusion in ELF discussion is a factor-of-ten unit error, including the frequently misquoted 0.3–0.4 µT epidemiological threshold, which is 3–4 mG.

## Sources

- `nist-si` National Institute of Standards and Technology. *The International System of Units (SI), NIST Special Publication 330*. https://www.nist.gov/pml/special-publication-330 — government, link checked 2026-08-12
- `who-elf` World Health Organization (2007). *Electromagnetic fields and public health: exposure to extremely low frequency fields*. https://www.who.int/teams/environment-climate-change-and-health/radiation-and-health/non-ionizing/exposure — government, link checked 2026-08-12

Data licence: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Dataset version 2026.08.1. Retrieved from EMFBase, https://emfbase.com.

This record is reference data, not medical or legal advice. Regulatory limits, scientific guidelines and precautionary values are labelled separately and answer different questions.