Convert an angle between degrees, radians, gradians, and revolutions. Enter the value and its unit.
Usage Tip
To convert degrees to radians, multiply by pi and divide by 180; to go back, multiply by 180 and divide by pi.
Convert through degrees as the common base
Gradians (400 per turn) appear in some surveying.
Radians use pi, so common angles come out as fractions of pi.
One radian is about 57.3 degrees.
Angles can be measured in several units. A full circle is 360 degrees, 2 pi radians, 400 gradians, or one revolution. Degrees are the everyday choice, radians are standard in mathematics and programming, and revolutions are common for rotating machinery.
To convert degrees to radians, multiply by pi over 180, and to convert back, multiply by 180 over pi. Many calculators and programming languages expect radians for trigonometric functions, so entering a degree value there is a frequent source of wrong results. A right angle is 90 degrees, pi over 2 radians, 100 gradians, or a quarter of a revolution.