Excel ATAN2 Function
The ATAN2 function calculates the arctangent (inverse tangent) of the specified x- and y-coordinates, and returns an angle, in radians, in the range from -π/2 to π/2.
The ATAN2 function returns a numeric value.
- The result is an angle expressed in radians. To convert the angle from radians to degrees, use the DEGREES function, or multiply the result by 180/PI().
- A positive result represents a counterclockwise angle from the x-axis; and a negative result represents a clockwise angle.
- ATAN2 returns the #DIV/0! error if both x_num and y_num are 0 (zero).
- ATAN2 returns the #VALUE! error if x_num or y_num is not numeric.
To calculate the arctangent (inverse tangent) of the specified x- and y-coordinates listed in the table as shown below, please copy or enter the below formula in the top cell (E6) of the result list, and press Enter to get the result. Then select the result cell, and drag the fill handle (the small square in the lower-right corner of the selected cell) down to apply the formula to the below cells.
Instead of cell references, you can type the actual x_num and y_num values in the formula as shown below.
Note that the results are angles expressed in radians. You can nest the ATAN2 function into a DEGREES function to convert the angles from radians to degrees as shown below.
Alternatively, you can multiply ATAN2 by 180/PI().