MS Excel: ATN Function (VBA)

This Excel tutorial explains how to use the Excel ATN function with syntax and examples.


The Microsoft Excel ATN function returns the arctangent of a number.


The syntax for the Microsoft Excel ATN function is:

Atn( number )

Parameters or Arguments

number is a numeric expression.

Applies To

The ATN function can be used in the following versions of Microsoft Excel:

  • Excel 2013, Excel 2011 for Mac, Excel 2010, Excel 2007, Excel 2003, Excel XP, Excel 2000

Type of Excel Function

The ATN function can be used in Microsoft Excel as the following type of function:

  • VBA function (VBA)

Example (as VBA Function)

The ATN function can only be used in VBA code in Microsoft Excel.

Let's look at some Excel ATN function examples and explore how to use the ATN function in Excel VBA code:

Result: 1.10714871779409

Result: 1.19166451926354

Result: -1.27229739520872

For example:

Dim LNumber As Double

LNumber = Atn(210)

In this example, the variable called LNumber would now contain the value of 1.56603445802574.