Here is a PowerShell script that will list the mount points in Windows along with Capacity in GB, Free space in GB, Free space in %.
gwmi win32_volume|where-object {$_.filesystem -match “ntfs”}|ft name,@{Name=”Capacity(GB)”;expression={[math]::round(($_.Capacity/ 1073741824),2)}},@{Name=”FreeSpace(GB)”;expression={[math]::round(($_.FreeSpace / 1073741824),2)}},@{Name=”Free(%)”;expression={[math]::round(((($_.FreeSpace / 1073741824)/($_.Capacity / 1073741824)) * 100),0)}}

does not work with folders assigned to a drive