SharePoint Site Detailed Storage Report using PowerShell

Requirement: Generate a detailed report on all list and library sizes of a SharePoint site.

Solution: PowerShell script! Here is the PowerShell script to generate detailed storage information with listing all list and library sizes.

#Get Size of all lists and libraries in a SharePoint Site
[void][System.Reflection.Assembly]::LoadWithPartialName("Microsoft.SharePoint")

#Get-SPWeb cmdlet for MOSS 2007
Function global:Get-SPWeb($url)
{
  $site= New-Object Microsoft.SharePoint.SPSite($url)
        if($site -ne $null)
            {
               $web=$site.OpenWeb()        
            }
    return $web
}

#Function to Get Storage Metrics for a list/library 
Function GetStorageMetrics($Folder)
{   
    $TotalSize=0 
    #Get the size of each file in the folder
    foreach ($File in $Folder.Files)
    {
        #Get File Size
        $FileSize = $File.TotalLength

        $VersionSize=0
        #Get the Versions Size
        foreach ($FileVersion in $File.Versions)
        {
            $VersionSize += $FileVersion.Size
        }
        $TotalSize += $VersionSize+ $FileSize  
    }


      #Get Files in Sub Folders
        foreach ($SubFolder in $Folder.SubFolders)
        {   
         if($SubFolder.Name -ne "Forms") #Leave "Forms" Folder which has List default Aspx Pages.
             {
     #Call the function recursively for the subfolders
                $TotalSize += GetStorageMetrics($SubFolder)          
             }
        } 

        #Return the object
     return $TotalSize
}

#Set Site URL  variable
$WebURL = "http://sharepoint.crescent.com"
#Get the Web
$Web = Get-SPWeb $WebURL

#Array to hold Storage data for all lists and libraries
$StorageDataCollection = @() 

foreach($List in $Web.Lists)
 {
    #Leave the Hidden Lists and exclude certain Libraries
    if($List.Hidden -eq $false)
    {
        #Write-host "Procesing list:" $list.title
        #Call the function to get library's Size relatedMetrics
        $LibrarySize = GetStorageMetrics($List.RootFolder)

        #Create an object to hold storage data
        $StorageDataResult = New-Object PSObject

        #Add other details of the list 
        $StorageDataResult | Add-Member -type NoteProperty -name "List/Library Name" -value $List.Title
        $StorageDataResult | Add-Member -type NoteProperty -name "Item/File Count" -value $List.ItemCount
        $StorageDataResult | Add-Member -type NoteProperty -name "Created by" -value $List.Author
        $StorageDataResult | Add-Member -type NoteProperty -name "Created on" -value $List.Created
        $StorageDataResult | Add-Member -type NoteProperty -name "Last Modified" -value $List.LastItemModifiedDate
        $StorageDataResult | Add-Member -type NoteProperty -name "URL" -value $List.DefaultViewUrl

        #Add storage related Data
        $StorageDataResult | Add-Member -type NoteProperty -name "Total Size (KB)" -value ([Math]::Round(($LibrarySize/1KB),2))

        #Add object to an array
        $StorageDataCollection += $StorageDataResult        
    }
 }

#Get Recycle bin size
$RecyclebinSize=0
foreach($RecycleBinItem in $Web.RecycleBin)
        {
           $RecyclebinSize += $RecycleBinItem.Size
        }
#Get the Total size of the library
$TotalSiteSize = ($StorageDataCollection | Measure-Object 'Total Size (KB)' -Sum | Select -expand Sum)


Write-host "Total Lists/Libraries Size in MB: "([Math]::Round(($TotalSiteSize/1KB),2))
write-host "Recycle bin Size in MB:" ([Math]::Round(($RecyclebinSize/1MB),2))
#Add recycle bin size
Write-host "Total site Size in MB: "([Math]::Round(($TotalSiteSize/1KB)+($RecyclebinSize/1MB),2))
write-host "Total Number of Lists/Libraries in the Site:" $Web.Lists.Count 

#export the detailed storage Info the CSV file
$StorageDataCollection | sort-object "Total Size" -descending | Export-csv "SiteStroageRpt.csv" -notypeinformation
Write-host "Site Storage Report has been generated!"

$Web.dispose()

This script generates the report in CSV format. Here is a snapshot after exporting to Excel:
It also gives the total size of lists, libraries and size of the recycle bin.