The Excel ATAN2 function calculates the arctangent (i.e. the inverse tangent) of a given set of x and y coordinates, and returns an angle, in radians, between -π/2 and +π/2.
The syntax of the function is:
Where the x_num and y_num arguments are the x- and y- coordinates of the point that you want to calculate the arctangent of.
Note: the angle returned from the Atan2 function may be positive (representing a counterclockwise angle from the x-axis), or negative (representing a clockwise angle from the x-axis). This result is given in radians.
Converting from Radians to DegreesAn example of this is provided below.
Column A of the following spreadsheet shows examples of the Excel Atan2 Function, used to calculate the arctangent of different x- and y- coordinates.
Note that in the example in cell A4, the Excel Degrees function is used to convert the calculated angle from radians to degrees.
For further information and examples of the Excel Atan2 function, see the Microsoft Office website.
If you get an error from the Excel Atan2 Function, this is likely to be one of the following:
|#DIV/0!||-||Occurs if the supplied x_num and y_num arguments are both equal to 0.|
|#VALUE!||-||Occurs if one or both of the supplied arguments are non-numeric.|