Conversion between Degrees and Milliradians
Multiply by 17.45. One degree is π/180 of a radian, which is 17.4533 milliradians, so 5° is about 87.27 mrad and half a degree about 8.73 mrad.
In your head, multiply by 17.5. It's 0.3% high, which nobody at a rifle range will notice.
The reason anyone bothers with milliradians is that 1 mrad covers 1 m at a distance of 1,000 m. Military mils are often 6,400 to the circle rather than the true 6,283, so check which your scope means.
About Degrees
Degrees (symbol: °) are a unit of measurement used to quantify angles in geometry and trigonometry. An angle is formed when two lines or rays intersect, and degrees are used to measure the amount of rotation between these lines or rays. The concept of degrees dates back to ancient civilizations, with the Babylonians being credited with the development of the sexagesimal system, which divided a circle into 360 equal parts.
In the sexagesimal system, a full circle is divided into 360 degrees, with each degree further divided into 60 minutes (symbol: '). Each minute is then divided into 60 seconds (symbol: "). This system allows for precise measurement of angles, with smaller units providing greater accuracy. Degrees are commonly used in various fields, including mathematics, physics, engineering, and navigation.
Degrees are a versatile unit of measurement, allowing for easy conversion between different angular units. For example, radians, another commonly used unit for measuring angles, can be converted to degrees by multiplying the value by 180/π (approximately 57.3°). Similarly, degrees can be converted to radians by multiplying the value by π/180. This flexibility makes degrees a convenient choice for expressing angles in everyday life and scientific calculations.
About Milliradians
Milliradians, often abbreviated as mrad or mil, are a unit of measurement commonly used in fields such as military, engineering, and ballistics. Derived from the concept of a radian, which is a unit used to measure angles in a circle, a milliradian is equal to one-thousandth of a radian. This makes it a very precise unit for measuring small angles.
Milliradians are particularly useful in long-range shooting and artillery calculations. In these applications, milliradians are used to measure the angular size of a target or the angular deviation of a projectile's trajectory. By converting these angular measurements into milliradians, it becomes easier to make accurate adjustments and calculations for aiming and targeting.
One of the advantages of using milliradians is that they are a dimensionless unit, meaning they do not depend on the distance to the target. This makes milliradians a versatile and consistent unit of measurement, allowing for easy comparison and calculation across different ranges. Additionally, milliradians are often used in conjunction with metric units, making them compatible with the International System of Units (SI).
In summary, milliradians are a precise and widely used unit of measurement for small angles. Their applications range from military and ballistics to engineering and surveying. With their dimensionless nature and compatibility with metric units, milliradians provide a reliable and standardized method for measuring and calculating angles in various fields.
Note that there are several variants of Milliradians, namely NATO Mils, USSR Mils, US WW2 Mils and UK Mils. Information on these variants are available from the links on this page.