PowerShell: Get Folder Size on Windows

You can use PowerShell to calculate the exact size of a specific folder in Windows (recursively, including all subfolders). This way you can quickly find out the size of the directory on disk without using third-party tools such as TreeSize or WinDirStat. In addition, PowerShell gives you more flexibility to filter or exclude files (by type, size, or date) that you need to consider when calculating folder size.

Use the following PowerShell cmdlets to calculate the size of a folder:

• Get-ChildItem (gci alias) — gets a list of files (with sizes) in a directory (including nested subfolders). Previously, we showed you how to use the Get-ChildItem cmdlet to find the largest files on the disk.
• Measure-Object (measure alias) – sums the sizes of all files to get the total directory size.

For example, to find the size of the D:\ISO directory in GB, run:

(Get-ChildItem D:\ISO -force -Recurse -ErrorAction SilentlyContinue| measure Length -sum).sum / 1Gb

Parameters used:

• -Force – include hidden and system files
• -Recure – get a list of files in subfolders
• -ErrorAction SilentlyContinue – ignore files and folders the current user is not allowed to access
• -measure Length -sum – a sum of all file sizes (the Length property)
• .sum/ 1Gb – show total size in GB

In this example, the directory size is about 37 GB (this PowerShell command ignores NTFS file system compression if it is enabled).

To round the results to two decimal places, use the command:

"{0:N2} GB" -f ((Get-ChildItem D:\ISO -force -Recurse -ErrorAction SilentlyContinue| measure Length -sum).sum / 1Gb)

PowerShell can find the total size of all files of a particular type in a directory. For example, add the *.iso parameter to find out how much space is taken up by ISO files:

"{0:N2} GB" -f ((Get-ChildItem D:\ISO *.iso -force -Recurse -ErrorAction SilentlyContinue| measure Length -sum).sum / 1Gb)

You can use other filters to select files to be included in the directory size calculation. For example, to see the size of files in the directory created in 2024:

(gci -force D:\ISO –Recurse -ErrorAction SilentlyContinue | ? {$_.CreationTime -gt '1/1/24’ -AND $_.CreationTime -lt '12/31/24'}| measure Length -sum).sum / 1Gb

If there are symbolic or hard links in the directory, the above PowerShell cmdlet displays an incorrect folder size. For example, the C:\Windows directory contains many hard links to files in the WinSxS folder (Windows Component Store). Such files may be counted several times. Use the following command to ignore hard links:

"{0:N2} GB" -f ((gci –force C:\Windows –Recurse -ErrorAction SilentlyContinue | Where-Object { $_.LinkType -notmatch "HardLink" }| measure Length -s).sum / 1Gb)

Get the sizes of all top-level subfolders in the destination folder and the number of files in each subfolder (in this example, the PowerShell script displays the size of all user profiles in C:\Users):

$targetfolder='C:\Users'
$dataColl = @()
gci -force $targetfolder -ErrorAction SilentlyContinue | ? { $_ -is [io.directoryinfo] } | % {
    $len = 0
    gci -recurse -force $_.fullname -ErrorAction SilentlyContinue | % { $len += $_.length }
    $filesCount = (gci -recurse -force $_.fullname -File -ErrorAction SilentlyContinue | Measure-Object).Count
  $dataObject = New-Object PSObject -Property @{
        Folder = $_.fullname
        SizeGb = ('{0:N3}' -f ($len / 1Gb)) -as [single]
        filesCount=$filesCount
    }
   $dataColl += $dataObject
   }
$dataColl | Out-GridView -Title "Subfolder sizes and number of files"

The script will display the Out-GridView graphical table listing the directories, their sizes, and how many files they contain. The folders in the table can be sorted by size or number of files in the Out-GridView form. You can also export the results to a CSV  (| Export-Csv folder_size.csv) or to an Excel file.