Below you may find a simple way to pick up the folder size and subfolder sizes in PowerShell.

function Get-FolderSizeTree {
        <#
        .SYNOPSIS
        Retrieves folder size information in a structured way. 
        .DESCRIPTION
        Retrieves folder size information in a structured way.
        .EXAMPLE
        PS C:\> Get-FolderSizeTree .\sdwork\ | ft

        ParentName  Name                        SizeMB SizeGB
        ----------  ----                        ------ ------
        .\sdwork\                                36.19   0.04
                    C:\sdwork                    29.58   0.03
                    C:\sdwork\binwin              1.33      0
                    C:\sdwork\bsddb               0.06      0
                    C:\sdwork\bsddb\test          0.09      0
                    C:\sdwork\compiler            0.15      0
                    C:\sdwork\distutils           0.34      0
                    C:\sdwork\distutils\command   0.18      0
                    C:\sdwork\email               0.13      0
                    C:\sdwork\email\test           0.1      0
        #>
        [CmdletBinding()] 
        param (
                [parameter(mandatory=$true,ValueFromPipeline = $true, ValueFromPipelineByPropertyName = $true )] 
                [System.IO.DirectoryInfo[]]$Name,
                [Switch]$ShowNonEmptyDirsOnly,
                [Switch]$SortBySize
                )

                BEGIN{}
                PROCESS{
                foreach($name1 in $name){  

                        $out2 = Get-ChildItem -Force -Recurse $Name1 -File | 
                            Select-Object LastWriteTime, @{n='SizeMB'; e={[math]::round(($_.length / 1MB),3)}}, name, directory | 
                                Group-Object directory | 
                                    Select-Object @{n='ParentName';e={$Null}},  Name, 
                                        @{n='SizeMB' ; e={[math]::Round((($_.group.sizeMB | Measure-Object -Sum).sum),3)}} , 
                                            @{n='SizeGB' ; e={[math]::Round((($_.group.sizeMB | Measure-Object -Sum).sum/1024),3)}}
                        
                        $out1 = "" | Select-Object @{n='ParentName';e={$Name1}}, 
                                        @{n='Name';e={$Null}},  
                                            @{n='SizeMB';e={[math]::Round((($out2.SizeMB | Measure-Object -sum).sum),3)}}, 
                                                @{n='SizeGB' ; e={[math]::Round((($out2.sizeMB | Measure-Object -Sum).sum/1024),3)}}
                        
                        $Total = @()
                        $Total += $out1
                        $Total += $out2

                        IF($ShowNonEmptyDirsOnly){
                            IF($SortBySize){ $Total | ?{$_.sizeMB -gt 0} | Sort-Object -Property SizeMB }ELSE{ $Total | ?{$_.sizeMB -gt 0 } }
                        }ELSE{
                            IF($SortBySize){ $Total | Sort-Object -Property SizeMB }ELSE{ $Total }
                        }
                        
                    }
                }
                END{}
}