Excel ATN Function

The Excel ATN function returns arctangent (inverse tangent) of a number. It returns result expressed in radians.

The ATN function is a built-in function in Excel that is categorized as a Math/Trig Function. It can be used as a VBA function in Excel. As a VBA function, this function can be used in a Excel macro code. The Excel macro code can be created using the Microsoft Visual Basic Editor.

Syntax

ATN(number)

Parameters

Return Value

Returns the arctangent of a value.

Notes

• To convert the result in degrees, multiply it by 180/PI or use the DEGREES function.

Example: Using as VBA Function

The ATN function can be used in VBA code in Microsoft Excel. Consider the example below:

Dim FValue As Double

FValue = ATN(1)

In this example, the variable called FValue will contain the value of 0.785398163397448.

Similarly, for the different input the VBA code will give the following output:

ATN(2)
Result: 1.107148718

ATN(2.5)
Result: 1.19028995

ATN(0)
Result: 0

ATN(-2)
Result: -1.107148718

ATN(-2.5)
Result: -1.19028995

Example: Convert Result to Degrees

To get the result from ATN function in degrees, the result can be multiplied by 180/PI. Alternatively, the angle can be converted into degrees by using DEGREES function. For example, to convert 2 radians into degrees, the following expression can be used in VBA code:

2 * 180 / WorksheetFunction.Pi
Result: 114.591559026165

WorksheetFunction.Degrees(2)
Result: 114.591559026165