Powershell script to get the total size of a list of folders and the last modified date of the newest file in each folder. The script takes a CSV input file which needs to be a list of paths with a header of "path".

Get-FolderSize.ps1

[CmdletBinding()]
param (
    $Paths = (Import-CSV "Paths.csv")
)

$i = 0
$Total = 0

$Paths | ForEach-Object {
        
    Write-Progress -Activity "Getting folder size for $($_.Path)" -PercentComplete (($i / $Paths.Count) *100) -Status ("Total size -- " + "{0:N2}" -f $Total + "MB")

    $subFolderItems = (Get-ChildItem $_.path -Recurse)
    $FolderSize = ($subFolderItems | Measure-Object -property length -sum | Select Sum -ExpandProperty Sum) / 1MB
    $NewestFile = $subFolderItems | sort LastWriteTime | select -last 1

    $Result = @{
        Path = $_.path
        SizeMB = $FolderSize
        LastWritten = $NewestFile.LastWriteTime
    }
    New-Object PSObject -Property $Result
    
    Write-Verbose ("$($_.path) -- " + "{0:N2}" -f $FolderSize + "MB")
    $Total += $FolderSize
    $i++

} | Export-CSV "Paths-Sizes.csv"