The Excel ATAN2 function returns the arctangent from the x and y coordinates of a point. In geometric terms, the function returns the radian angle corresponding to the coordinates of the input point. If you imagine a ray starting from the origin of the coordinate system and extending outwards, every point along the ray will return the same angle value. A circle of radius one demonstrates all possible return values for the function.
For negative y-values the function returns a negative angle. An angle is measured from the positive x-axis direction with the positive direction in the counter-clockwise direction and the negative direction in the clockwise direction.
Convert Output to Degrees
To convert the output of the ATAN2 function from radians to degrees the formula is: