EMFBase
Glossary

µW/m², mW/m² and mW/cm²

Three units for the same RF quantity, spanning ten orders of magnitude: 1 mW/cm² = 10 W/m² = 10,000 mW/m² = 10,000,000 µW/m².

measurement

Last verified 12 August 2026.

Category
measurement

Definition

Consumer RF meters report µW/m² or mW/m², ICNIRP uses W/m², and FCC rules use mW/cm². A reading of 10,000 µW/m² is 0.01 W/m², which is 0.001 mW/cm² — one ten-thousandth of the FCC's 10 mW/cm² public limit above 1.5 GHz. Failing to convert is the single most common error in EMF discussion in both directions.

Sources

  1. nist-si The International System of Units (SI), NIST Special Publication 330 — National Institute of Standards and Technology. government, link checked 2026-08-12.
  2. fcc-1310 47 CFR § 1.1310 — Radiofrequency radiation exposure limits — U.S. Government Publishing Office (eCFR). regulation, link checked 2026-08-12.
  3. icnirp-2020 Guidelines for Limiting Exposure to Electromagnetic Fields (100 kHz to 300 GHz) — International Commission on Non-Ionizing Radiation Protection, 2020. guideline, link checked 2026-08-12.

Same record, other formats