The three units
A full turn is 360 degrees, 2 pi radians or 400 gradians.
Degrees suit everyday use, radians are what calculus needs, and gradians were designed so a right angle is a round 100.
Worked example
45 degrees is 0.78539816 radians and 50 gradians.
Its complement is 45 degrees, because 90 - 45 = 45, and its supplement is 135 degrees, because 180 - 45 = 135.
Complement and supplement
Two angles are complementary when they add to 90 degrees, and supplementary when they add to 180.
A complement only exists for an angle between 0 and 90 degrees, so the row is left out for larger angles.
Inputs for the angle calculator
Angle
The angle you have. It can be negative or larger than a full turn.
Unit
The unit your angle is in. The answer is given in degrees, radians and gradians.
CALCULATOR QUESTIONS
Angle calculator questions
How do I convert degrees to radians?
Multiply by pi and divide by 180. 45 degrees is 0.78539816 radians.
What is a gradian?
A unit where a right angle is 100, so a full turn is 400 gradians.
What is the complement of 45 degrees?
45 degrees, because the two add up to 90.
Can an angle be more than 360 degrees?
Yes. Angles larger than a full turn appear when something rotates more than once.