Trigonometry

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.

Angle Converter

Convert degrees and radians, with reference angle.

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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°).