PowerShell list folders sizes

folders_usage.ps1

# usage: .\folders_usage.ps1 'C:\Program Files (x86)\' -Tree 2
param(
    [Parameter(Mandatory=$true, Position=0)]
    [string]$Folder,

    [int]$Tree = 0
)

if (-not (Test-Path $Folder)) {
    Write-Error "Folder '$Folder' does not exist."
    exit
}

# Cache folder sizes
$FolderSizes = @{}

function Get-FolderSize {
    param([string]$Path)

    if ($FolderSizes.ContainsKey($Path)) {
        return $FolderSizes[$Path]
    }

    $size = (Get-ChildItem $Path -Recurse -File -ErrorAction SilentlyContinue |
             Measure-Object Length -Sum).Sum

    $FolderSizes[$Path] = $size
    return $size
}

# Format size as GB string, but return raw text (no padding)
function Format-Size {
    param([long]$Bytes)

    $gb = [math]::Round($Bytes / 1GB, 2)
    return ("{0:0.##} GB" -f $gb)
}

# Width of the left column (tree + folder name)
$LeftWidth = 60

# Width of the size text inside brackets
$SizeWidth = 10   # adjust if needed

function Get-Tree {
    param(
        [string]$Path,
        [int]$Level,
        [int]$MaxLevel,
        [string]$Prefix = ""
    )

    if ($Level -gt $MaxLevel) { return }

    $dirs = Get-ChildItem $Path -Directory -ErrorAction SilentlyContinue

    for ($i = 0; $i -lt $dirs.Count; $i++) {

        $isLast = ($i -eq $dirs.Count - 1)
        $connector = if ($isLast) { "└── " } else { "├── " }

        $left = "$Prefix$connector$($dirs[$i].Name)"

        $size = Get-FolderSize $dirs[$i].FullName
        $sizeText = Format-Size $size

        # Right-align inside brackets
        $sizeAligned = ("{0,$SizeWidth}" -f $sizeText)

        # Final line
        $line = ("{0,-$LeftWidth} [{1}]" -f $left, $sizeAligned)
        Write-Output $line

        $newPrefix = if ($isLast) { "$Prefix    " } else { "$Prefix│   " }

        Get-Tree -Path $dirs[$i].FullName -Level ($Level + 1) -MaxLevel $MaxLevel -Prefix $newPrefix
    }
}

# Warm cache (no output)
Get-ChildItem $Folder -Directory | ForEach-Object {
    Get-FolderSize $_.FullName | Out-Null
}

# Tree mode
if ($Tree -gt 0) {
    Write-Host ""
    Write-Host "Directory tree (max depth: $Tree)" -ForegroundColor Cyan

    $rootSize = Get-FolderSize $Folder
    $rootText = Format-Size $rootSize
    $rootAligned = ("{0,$SizeWidth}" -f $rootText)

    Write-Host ("{0,-$LeftWidth} [{1}]" -f $Folder, $rootAligned)

    Get-Tree -Path $Folder -Level 1 -MaxLevel $Tree
}