Atan2 Calculator

About this calculator

The two-argument arctangent, atan2(y, x), solves a problem the ordinary arctangent can't: atan(y/x) alone can't tell you which quadrant a point sits in, because the ratio y/x gives the same value whether both y and x are positive or both are negative. atan2 takes the x and y coordinates separately rather than their ratio, so it can return the correct full angle — from −180° to 180° (or −π to π radians) — no matter which of the four quadrants the point falls in.

Programming languages and math libraries expose atan2 as a standard function precisely because of this quadrant-correctness, and it's used throughout computer graphics and game development to compute an object's facing angle from a direction vector, in robotics and navigation to calculate heading or bearing between two coordinates, and anywhere else an angle needs to be recovered reliably from x and y components.

This calculator takes x and y coordinates and returns the angle in both degrees and radians.