Convert Mils (NATO) to Radians

Mils (NATO)

A mil, short for milliradian, is equal to 1/6,400 of a circle. The mil used by the US military and NATO forces is slightly different than the true value of a milliradian, which is equal to 1/6,283 of a circle.

During World War I the US adopted what is now the NATO mil to replace degrees and minutes for use in artillery sights. They opted to round mils to 6,400 per circle for simplicity at the time. Today, the mil is commonly used to measure adjustment of sights and scopes of firearms.

There is rightfully much confusion as a result of the mil adopted by the US military and NATO being slightly different than the milliradian.

A mil is sometimes also referred to as an angular mil. Mils (NATO) can be abbreviated as mil, for example 1 mil can be written as 1 mil.

Radians

A radian is the measurement of angle equal to the start to the end of an arc divided by the radius of the circle or arc. 1 radian is equal to 180/π, or about 57.29578°. There are about 6.28318 radians in a circle.

The radian is the SI derived unit for angle in the metric system. Radians can be abbreviated as rad, and are also sometimes abbreviated as ^c, r, or ^R. For example, 1 radian can be written as 1 rad, 1 ^c, 1 r, or 1 ^R.

Radians are often expressed using their definition. The formula to find radians is θ = s/r, where the angle in radians θ is equal to the arc length s divided by the radius r. Thus, radians may also be expressed as the formula of arc length over the radius.