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

### Description

The Excel ATAN function returns the arctangent of a number. So this function can be used to calculates the arctangent of a supplied number. The returned angle is given in radians in the range –pi/2 to pi/2. Or the returned value is a numeric value.

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

The ATAN 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 ATAN function is as below:

=ATAN(number)

Where the ATAN function arguments is:

**number**-This is a required argument. The tangent of the angle that you want to get.

**Note:**

- 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。

### Excel ATAN Function Examples

The below examples will show you how to use Excel ATAN Function to return the arctangent for a given number.

**1#** get the arctangent of 2 in radians, pi/4, enter the following formula in Cell B1.

**=ATAN(2)**

The returned result is 1.107149.

**2#** get the arctangent of 2 in degrees, using the following formula in Cell B2.

=ATAN(2)* 180/PI()

This formula will return the value 63.43495.

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

=DEGREES(ATAN(2))

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