Angle Converter
Convert between radians, degrees and gradians
How to use the angle converter
Type in the angle in the field you want to convert from. As you type the converted values will show up in the othe two fields. You can also type mathematical expressions in the input fields, e.g. if you type pi/4 in the radians field it will give 45 degress and 50 gradians.
 About the units:

Radians  The standard unit for angles. It is defined as the angle when the arc is the same length as the radius. Therefore, an entire revolution expressed in radians, is 2π.
More info on radians: http://en.wikipedia.org/wiki/Radian
Degrees  The origin of degrees as an angle unit is not completely known. An entire revolution is 360 degrees, so one degree is equal to 2π/360=π/180≈0.01745 radians.
More info on degrees as an angle unit: http://en.wikipedia.org/wiki/Degree_(angle)
Gradians  Also called gon. This unit originates from France. An entire revolution is 400 gradians. An advantage using gradians as an angle unit is it allows for easier mental calculation since it's based on hundreds. One gradian is equal to 2π/400=π/200≈0.01571 radians and 360/400=0.9°
More info on gradians: http://en.wikipedia.org/wiki/Grad_(angle)