How it works
Convert angles between degrees, radians, gradians, arcminutes, arcseconds, milliradians and full turns. Radians are the natural unit in mathematics and programming; degrees are used in everyday work; gradians divide a right angle into 100 parts and appear in some surveying.
A full circle is 360°, 2π radians, 400 gradians or 1 turn. Shooters often use arcminutes (MOA, 1/60 of a degree) and milliradians (mils) for scope adjustments: 1 MOA covers about 1.047 inches at 100 yards and 1 mrad covers 10 cm at 100 m.
Formula
Radians = degrees × π ÷ 180; gradians = degrees × 10 ÷ 9
Questions people ask
How do I convert degrees to radians?
Multiply by π/180. For example, 90° × π/180 = π/2 ≈ 1.5708 rad.
How many degrees is one radian?
About 57.2958°. A radian is the angle where the arc length equals the radius.
What is the difference between a mil and a milliradian?
A true milliradian is 1/1000 radian, so there are about 6,283 in a circle. NATO military "mils" round this to 6,400 per circle, and other countries have used 6,000 or 6,300.