# Excel ATAN2 Function

This post will guide you how to use** Excel ATAN2 function** with syntax and examples in Microsoft excel.

### Description

The Excel ATAN2 function returns the arctangent, or inverse tangent, of the specified x- and y-coordinates. And you can use the ATAN2 function to calculate the arctangent of a given x and y coordinates. The returned value is an angle between –pi/2 and pi/2.

The ATAN2 function is a build-in function in Microsoft Excel and it is categorized as a Math and Trigonometry Function.

The ATAN2 function is available in Excel 2016, Excel 2013, Excel 2010, Excel 2007, Excel 2003, Excel XP, Excel 2000, Excel 2011 for Mac.

### Syntax

The syntax of the ATAN2 function is as below:

=ATAN2(x_num, y_num)

Where the ATAN2 function arguments are:

**x_num**-This is a required argument. The x-coordinate of a point.**Y_num**– This is a required argument. The y-coordinate of a point.

**Note:**

- If the values of both x_num and y_num arguments are 0, the ATAN2 will return the #DIV/0! Error.
- The returned value of ATAN2(a,b) is equal to the formula ATAN2(b,a).
- If you want to express the arctangent in degrees, you just need to multiply the result by 180/PI() or you can use the DEGREES function.
- If the supplied number is not a numeric value, the ATAN function will get the #VALUE！ Error。
- If the returned result is a positive value, it indicates that it is a counterclockwise angle from the x-axis. If the returned result is a negative value, it indicates that it is a clockwise angle.

### **Excel ****ATAN2** **Function Examples**

The below examples will show you how to use Excel ATAN2 Function to return the arctangent of x and y coordinates.

**1#** get the arctangent of the x- and y-coordinates 2,2 in radians, enter the following formula in Cell B1.

=ATAN2(2,2)

The returned result is 0.785398.

**2#** get the arctangent of the x- and y-coordinates -2,-2 in radians, -3*pi/4, using the following formula in Cell B2.

=ATAN2(-2,-2)

This formula will return the value -2.35619.

**3#** get the arctangent of the x- and y-coordinates 2,2 in degrees, using the following formula in Cell B3.

=ATAN2(2,2)*180/PI()

Or you can use the below formula to achieve the same result:

=DEGREES(ATAN2(2.2))

### Related Functions

- Excel ATAN function

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