micron [µ] Unit Converter

Definition of micron [µ] unit

A micron, now officially called a micrometre (µm), is a metric unit of length equal to one-millionth of a metre, or 0.001 millimetre. It measures microscopic dimensions, such as cell sizes, fiber diameters, particle widths, and thin coating thicknesses.

History of micron [µ] unit

The word micron originated in the nineteenth century from the Greek mikron, meaning “small,” and was adopted as a name for a millionth of a metre. The symbol µ was commonly used, often written µm. In 1967, the International System of Units (SI) officially replaced “micron” with “micrometre,” using the metre-based prefix micro-, symbol µ, to express 10−6. Although “micron” remains widespread in science, engineering, manufacturing, and everyday technical language, “micrometre” is the preferred formal designation in modern standards and metrology.

Applications of micron [µ] unit

Microns are used wherever very small dimensions matter. They describe biological cells, bacteria, dust and aerosol particles, semiconductor features, optical wavelengths, printer resolution, textile fibers, and filtration ratings. Engineers specify micrometre tolerances for precision components, while manufacturers use the unit for coatings, membranes, surface roughness, and machining accuracy. Air-quality and laboratory instruments also report particle sizes in microns.

Complete list of micron [µ] unit conversion