A milliradian (mil) is an angular measurement equal to one-thousandth of a radian. In practical terms, one mil subtends approximately 3.6 inches at a distance of 100 yards. This relationship provides a convenient way to estimate range or size of objects at known distances, particularly in long-range shooting and military applications. For instance, if an object observed through a telescopic sight with mil-dot reticle appears to be 2 mils wide, and the observer knows the object is approximately 2 yards wide, the distance to the object can be readily estimated.
This angular measurements utility stems from its simplified calculations and direct correlation to linear dimensions at specific distances. It allows for quick adjustments to aiming devices without requiring complex mathematical conversions. Historically, the mil has been employed extensively by military forces worldwide for artillery ranging and target acquisition. Its practicality and precision continue to make it an essential tool for marksmen, hunters, and other professionals working with long-range optics.