PowerShell: Get Folder Sizes on Disk in Windows

gci -force ‘D:\video’-ErrorAction SilentlyContinue | ? { $_ -is [io.directoryinfo] } | % {
$len = 0
gci -recurse -force $_.fullname -ErrorAction SilentlyContinue | % { $len += $_.length }
$_.fullname, ‘{0:N2} GB’ -f ($len / 1Gb)
}