Basic powershell script to get folder sizes in current dir (depth 1).

get_foldersizes.ps1

Get-ChildItem -Directory | ForEach-Object {
    echo "Folder: $($_.Name)"
    echo "Size: $((Get-ChildItem $_.Name -Recurse | Measure-Object -Property Length -Sum).Sum/(1024*1024*1024))GiB"
    echo ""
 }