Convert between different units of angles including degrees, radians, gradians, minutes, seconds, and more.
The 360-degree system originated from ancient Babylonian astronomy, based on their approximation of the year as 360 days. Each degree represented one day's apparent movement of the Sun around Earth.
One radian is the angle subtended at the center of a circle by an arc equal in length to the radius. A full circle is 2π radians (approximately 6.28318 radians), making π radians equivalent to 180 degrees.
The gradian (also called grade or gon) was introduced during the French Revolution as part of the metric system. A full circle is 400 gradians, with 100 gradians in a right angle, making decimal calculations easier.
In navigation, bearings are expressed as angles in degrees clockwise from North (0°). A bearing of 90° is East, 180° is South, and 270° is West. Military and aviation often use the "mils" unit, with 6400 mils in a full circle.