millimeetrit

Millimeetrit is the unit of length in the metric system equal to one thousandth of a meter. It is commonly abbreviated as mm and is part of the International System of Units (SI). The name combines the prefix milli- (one thousandth) with the base unit metre.

In terms of meters, one millimetre equals 0.001 m. Submultiples and related units include the micrometre (0.001 mm) and the centimetre (10 mm). Conversely, one metre equals 1000 millimetres. The millimetre is widely used for measuring small distances and thicknesses in science, engineering, manufacturing, and everyday life.

Typical measurements expressed in millimetres include the thickness of paper (roughly 0.05–0.1 mm for thin paper, up to ~0.3 mm for card stock), the diameter of small screws or wires, and the thickness of objects such as smartphone panels or glass. Precision instruments such as calipers and micrometers provide measurements in millimetres, often with decimal fractions to indicate submillimetre accuracy.

History and usage: the millimetre emerged with the broader adoption of the metric system in the 18th and 19th centuries and was formalized within SI definitions in the 20th century. It remains the standard unit for many measurements where small, precise lengths are required.

See also: metre, centimetre, micrometre, SI units.