Angle Converter
Enter an angle in degrees or radians. The converter gives the equivalent in the other unit, the coterminal angle in the range 0°–360°, the quadrant it lands in, and the reference angle used to relate it to first-quadrant trig values.
Frequently asked questions
How do degrees and radians relate?
A full turn is 360° or 2π radians, so 1° = π/180 radians.
What is a reference angle?
It is the acute angle between the terminal side and the x-axis — always between 0° and 90°.
What is a coterminal angle?
An angle that shares the same terminal side, differing by a whole number of full turns (multiples of 360°).