Excel - Microsoft Excel Atan2 Function

Description

The Excel ATAN2 function calculates the arctangent (ie. the inverse tangent) of a given set of x and y coordinates, and returns an angle, in radians, between -p/2 and +p/2. 

The format of the function is : 

ATAN2( x_num, y_num ) 

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 Degrees 

If you want the angle returned by the Atan2 function to be expressed in degrees, you can convert it, using the Excel Degrees function: 

=DEGREES( radians ) 

An example of this is included below. 

Excel Atan2 Function Examples

Column A of the spreadsheet below, shows examples of the Excel Atan2 Function, used to calculate the arctangent of different x- and y- coordinates. In the example in cell A4, the result is converted from radians, into degrees. 

The formulas are shown in the spreadsheet on the left and the results are shown in the spreadsheet on the right. 

Atan2 Function Common Errors

If you get an error from the Excel Atan2 Function, this is likely to be one of the following: 

Common Errors