How to Get Free Disk Space Using PowerShell (Complete Guide)

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Let me show you how to check free disk space using PowerShell. This is something I do almost daily, and it’s way more useful than clicking through Windows Explorer when you need to monitor multiple drives or servers.

Here are the reasons why we use PowerShell to check disk space.

  • You can check multiple drives at once
  • Easy to check remote computers
  • You can save the results to a file
  • Great for scheduling automated checks
  • Perfect when you need to track disk space over time

Now let’s get into the actual commands.

The Basic Command: Get-PSDrive

The simplest way to check disk space is using Get-PSDrive:

Get-PSDrive -PSProvider FileSystem

This shows all your drives with their used and free space. You’ll see something like this:

Name    Used (GB)     Free (GB)
----    ---------     ---------
C          156.23        743.77
D           45.89        454.11

You can see the exact output in the screenshot below:

powershell get disk space remote computer

It’s quick, it’s simple, and it works. But it’s pretty basic. Let me show you better options.

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The Better Option: Get-Volume

If you’re on Windows 8 or later (and you probably are), use Get-Volume:

Get-Volume

This command gives you more information about each drive, including the file system type and health status.

To see just your regular hard drives (not CD-ROMs or other stuff):

Get-Volume | Where-Object {$_.DriveType -eq 'Fixed'}

I exectued the above PowerShell script, and you can see the exact output in the screenshot below:

powershell get disk space in gb

Getting Free Disk Space in GB

Here’s where it gets practical. The default output sometimes shows bytes, which is hard to read. Let’s format it properly.

Using WMI (Works on All Windows Versions)

Get-WmiObject -Class Win32_LogicalDisk -Filter "DriveType=3" | 
Select-Object DeviceID, 
    @{Name="FreeSpace(GB)";Expression={[math]::Round($_.FreeSpace/1GB,2)}},
    @{Name="TotalSize(GB)";Expression={[math]::Round($_.Size/1GB,2)}}

Let me break this down:

  • Win32_LogicalDisk – This is the WMI class that stores disk information
  • DriveType=3 – This filters for local hard drives only (3 = local disk)
  • The @{Name=...Expression=...} part creates custom columns
  • /1GB converts bytes to gigabytes
  • [math]::Round(...,2) rounds to 2 decimal places

Using CIM (Newer Method)

If you’re on PowerShell 3.0 or later, use CIM instead of WMI:

Get-CimInstance -ClassName Win32_LogicalDisk -Filter "DriveType=3" |
Select-Object DeviceID,
    @{Name="Free(GB)";Expression={[math]::Round($_.FreeSpace/1GB,2)}},
    @{Name="Total(GB)";Expression={[math]::Round($_.Size/1GB,2)}}

You can see the exact output in the screenshot below:

powershell get disk usage by folder

CIM is faster and works better with remote computers. It’s basically the modern version of WMI commands.

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Getting Free Disk Space as a Percentage

This is really useful when you want to set up alerts or just quickly see which drives are getting full.

Get-CimInstance -ClassName Win32_LogicalDisk -Filter "DriveType=3" |
Select-Object DeviceID,
    @{Name="Free(GB)";Expression={[math]::Round($_.FreeSpace/1GB,2)}},
    @{Name="Total(GB)";Expression={[math]::Round($_.Size/1GB,2)}},
    @{Name="Free(%)";Expression={[math]::Round(($_.FreeSpace/$_.Size)*100,2)}}

The percentage calculation is simple: divide free space by total size, multiply by 100, and round it.

powershell getting free disk space as a percentage

Color-Coding Based on Free Space

Want to make it even better? Let’s add some visual feedback:

Get-CimInstance -ClassName Win32_LogicalDisk -Filter "DriveType=3" | ForEach-Object {
    $percentFree = [math]::Round(($_.FreeSpace/$_.Size)*100,2)

    if ($percentFree -lt 10) {
        Write-Host "$($_.DeviceID) - $percentFree% free" -ForegroundColor Red
    }
    elseif ($percentFree -lt 20) {
        Write-Host "$($_.DeviceID) - $percentFree% free" -ForegroundColor Yellow
    }
    else {
        Write-Host "$($_.DeviceID) - $percentFree% free" -ForegroundColor Green
    }
}

This shows red for drives below 10% free, yellow for under 20%, and green for everything else.

Tracking Disk Space Over Time

Here’s where PowerShell really shines. You can log disk space automatically and track how it changes.

Creating a Simple Log

$date = Get-Date -Format "yyyy-MM-dd HH:mm:ss"
Get-CimInstance -ClassName Win32_LogicalDisk -Filter "DriveType=3" |
Select-Object @{Name="Date";Expression={$date}},
    DeviceID,
    @{Name="Free(GB)";Expression={[math]::Round($_.FreeSpace/1GB,2)}},
    @{Name="Total(GB)";Expression={[math]::Round($_.Size/1GB,2)}},
    @{Name="Free(%)";Expression={[math]::Round(($_.FreeSpace/$_.Size)*100,2)}} |
Export-Csv -Path "C:\Logs\DiskSpace.csv" -Append -NoTypeInformation
powershell get disk space percentage log

This adds a timestamp and saves the results to a CSV file. Run this daily (or hourly), and you’ll build a history of your disk space usage.

Setting Up Scheduled Monitoring

Save the above script as Check-DiskSpace.ps1, then create a scheduled task to run it:

$action = New-ScheduledTaskAction -Execute 'Powershell.exe' -Argument '-File "C:\Scripts\Check-DiskSpace.ps1"'
$trigger = New-ScheduledTaskTrigger -Daily -At 9am
Register-ScheduledTask -Action $action -Trigger $trigger -TaskName "Daily Disk Space Check" -Description "Logs disk space daily"

Now you’ll automatically log disk space every day at 9 AM.

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Checking Disk Space on Remote Computers

Need to check disk space on other computers? PowerShell makes this easy.

Get-CimInstance -ClassName Win32_LogicalDisk -Filter "DriveType=3" -ComputerName "ServerName" |
Select-Object SystemName, DeviceID,
    @{Name="Free(GB)";Expression={[math]::Round($_.FreeSpace/1GB,2)}},
    @{Name="Total(GB)";Expression={[math]::Round($_.Size/1GB,2)}}

Replace “ServerName” with the actual computer name.

Checking Multiple Servers at Once

You can also check the disk space for multiple servers once in PowerShell:

$servers = "Server1", "Server2", "Server3"

foreach ($server in $servers) {
    Get-CimInstance -ClassName Win32_LogicalDisk -Filter "DriveType=3" -ComputerName $server |
    Select-Object SystemName, DeviceID,
        @{Name="Free(GB)";Expression={[math]::Round($_.FreeSpace/1GB,2)}},
        @{Name="Total(GB)";Expression={[math]::Round($_.Size/1GB,2)}}
}

This loops through all servers and shows disk space for each one.

Create Alerts for Low Disk Space

Here’s a practical script that sends you an email when disk space gets low:

$threshold = 20  # Alert when free space is below 20%

$lowDisks = Get-CimInstance -ClassName Win32_LogicalDisk -Filter "DriveType=3" | Where-Object {
    (($_.FreeSpace/$_.Size)*100) -lt $threshold
}

if ($lowDisks) {
    $emailParams = @{
        From = "alerts@yourcompany.com"
        To = "admin@yourcompany.com"
        Subject = "Low Disk Space Alert"
        Body = "The following drives are low on space:`n`n" + ($lowDisks | Out-String)
        SmtpServer = "smtp.yourcompany.com"
    }
    Send-MailMessage @emailParams
}

You’ll need to adjust the email settings for your environment, but this gives you the basic idea.

Making It Pretty: Creating a Function

If you do this often, create a function you can reuse:

function Get-DiskSpace {
    param(
        [string]$ComputerName = $env:COMPUTERNAME,
        [switch]$ShowPercentage
    )

    $disks = Get-CimInstance -ClassName Win32_LogicalDisk -Filter "DriveType=3" -ComputerName $ComputerName

    $result = $disks | Select-Object SystemName, DeviceID,
        @{Name="Free(GB)";Expression={[math]::Round($_.FreeSpace/1GB,2)}},
        @{Name="Total(GB)";Expression={[math]::Round($_.Size/1GB,2)}}

    if ($ShowPercentage) {
        $result | Select-Object *, @{Name="Free(%)";Expression={[math]::Round(($_.FreeSpace/$_.Size)*100,2)}}
    } else {
        $result
    }
}

Now you can just type:

Get-DiskSpace
Get-DiskSpace -ComputerName "Server1"
Get-DiskSpace -ShowPercentage

Much cleaner, right?

Common Issues and Solutions

Below are some common issues and their solutions; I got these errors while working with this.

  • “Access Denied” errors: You need admin rights to query disk information on remote computers.
  • WMI not working: Try CIM instead. It’s more reliable.
  • Slow on remote computers: Use -CimSession instead of -ComputerName if you’re checking multiple times. It’s faster because it reuses the connection.
  • Numbers look weird: Make sure you’re dividing by 1GB, not 1024MB. There’s a difference.

Conclusion

In this tutorial, I explained how to check disk space with PowerShell using different methods. You can start with the basic Get-Volume or Get-CimInstance commands, then build from there based on what you need.

The real power comes when you automate this stuff. Set up logging, create alerts, and monitor trends over time. Your future self will thank you when you can see that a drive has been slowly filling up rather than suddenly being full one day.

Do let me know in the comment below if you still have some questions.

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