mil [mil, thou] Unit Converter

Definition of mil [mil, thou] unit

A mil is a small angular unit used primarily for aiming and surveying. In the common military definition, one mil equals 1/6,400 of a full circle, or approximately 0.05625 degrees; other systems use slightly different subdivisions.

History of mil [mil, thou] unit

The angular mil emerged from the practical need to measure very small angles in artillery and field surveying. Early systems commonly approximated a milliradian, meaning one thousandth of a radian. Military organizations later standardized their own circle divisions for range estimation, with 6,400 mils per revolution becoming the NATO convention. Other countries adopted alternatives, including 6,000 mils in some former Soviet practice and 6,300 in Sweden. Despite these differences, the name “mil” generally reflects a thousandth or near-thousandth angular subdivision, rather than a universally identical value.

Applications of mil [mil, thou] unit

Mils are used with rifles, artillery, mortars, binoculars, rangefinders, and military maps to express minute angular corrections and estimate target distances. In a practical approximation, one mil subtends one meter at 1,000 meters. Hunters, shooters, and surveyors also use mil-based reticles, while engineering and navigation may use milliradians for precise alignment and measurement.

Complete list of mil [mil, thou] unit conversion