How to Add Calculated Column to SharePoint List using PowerShell

Requirement: Add new Calculated field to SharePoint list programmatically using PowerShell script.

PowerShell to add calculated column in SharePoint list or library:

Add-PSSnapin Microsoft.SharePoint.PowerShell –ErrorAction SilentlyContinue

#Variables
$WebURL="http://projects.crescent.com"
$ListName="Proposal Documents"
$CalculatedColumnName="Created Month-Year"

#Get the Web
$web = Get-SPWeb $WebURL

#Get the List
$list = $web.Lists.TryGetList($ListName)

#Add new calculated column
$list.Fields.Add($CalculatedColumnName, "Calculated", $false)

#Get the column
$CalculatedCol = $List.Fields.GetField($CalculatedColumnName)
#Set Formula for calculated column 
$CalculatedCol.Formula='=TEXT(Created,"mmm-YYYY")'
$CalculatedCol.OutputType="Text"
$CalculatedCol.Update()

$web.Dispose() 

Script in action: Create calculated column in SharePoint 2013 using PowerShell