How do I get the size of a file in PowerShell?

Run (Get-Item 'C:\path\file.txt').Length. It returns the size in bytes as an Int64; Microsoft documents it as the FileInfo.Length property .

How do I get a file size in MB in PowerShell?

Divide Length by 1MB: [math]::Round((Get-Item $path).Length / 1MB, 2). Use '{0:N2} MB' -f for display text.

Is 1KB in PowerShell 1000 or 1024 bytes?

It's 1024. The KB, MB, GB, TB and PB multipliers are powers of 1024, as listed in about_Numeric_Literals .

How do I get the size of all files in a folder?

Use Get-ChildItem $folder -File -Recurse | Measure-Object Length -Sum and read the Sum property.

Why does Length return 1 for a folder?

Folders have no Length property, so PowerShell returns its built-in count of 1 for a single object. Measure the files inside the folder instead.

Get the Size of a File in PowerShell (KB, MB, GB)

To get the size of a file in PowerShell, read the Length property of the file object that Get-Item returns. It’s the size in bytes:

(Get-Item 'C:\Reports\q3-deck.pptx').Length

Below I convert that number to KB, MB and GB, list and total the sizes in a folder, and cover three traps I hit while testing in PowerShell 7 and Windows PowerShell 5.1.

This Tutorial Covers:

Create sample files to follow along

You don’t need real files to practice. Open PowerShell in an empty test folder and run this to create a reports folder with three files of known sizes:

New-Item -ItemType Directory .\reports\archive -Force | Out-Null
[IO.File]::WriteAllBytes("$PWD\reports\q3-deck.pptx", (New-Object byte[] 5767168))
[IO.File]::WriteAllBytes("$PWD\reports\sales-2026.csv", (New-Object byte[] 48213))
[IO.File]::WriteAllBytes("$PWD\reports\notes.txt", (New-Object byte[] 812))

Get-ChildItem .\reports -File | ForEach-Object Name

Output:

notes.txt
q3-deck.pptx
sales-2026.csv

[IO.File]::WriteAllBytes writes a file of exactly that many bytes, so every number below is predictable. For more ways to list what’s in a folder, see the Get-ChildItem cmdlet.

Get the file size in bytes with Get-Item

Get-Item returns a FileInfo object, and its Length property holds the size. It’s an Int64, so files over 2 GB are fine:

$file = Get-Item .\reports\q3-deck.pptx
$file.Length
$file.Length.GetType().Name

Output:

5767168
Int64

5,767,168 bytes is exactly 5.5 MB. Don’t confuse this with the length of a string, which counts characters, not bytes.

How do I get the file size in KB, MB or GB?

PowerShell has built-in multipliers: 1KB is 1024, 1MB is 1024 squared, and 1GB is 1024 cubed. Divide by one of them, then round:

$bytes = (Get-Item .\reports\q3-deck.pptx).Length

"KB: $([math]::Round($bytes / 1KB, 2))"
"MB: $([math]::Round($bytes / 1MB, 2))"
"GB: $([math]::Round($bytes / 1GB, 4))"
"Formatted: {0:N2} MB" -f ($bytes / 1MB)

Output:

KB: 5632
MB: 5.5
GB: 0.0054
Formatted: 5.50 MB

PowerShell get file size in KB, MB and GB — One file size shown in KB, MB and GB (PowerShell 7)

[math]::Round keeps a number you can compare or sort. The -f format operator with N2 returns text with two decimals and a thousands separator. More options are in rounding to 2 decimal places.

Show file sizes in a readable format

For a report, pick the unit per file. This small function chooses GB, MB, KB or bytes based on the size:

function Format-FileSize ([long]$Bytes) {
    if     ($Bytes -ge 1GB) { '{0:N2} GB' -f ($Bytes / 1GB) }
    elseif ($Bytes -ge 1MB) { '{0:N2} MB' -f ($Bytes / 1MB) }
    elseif ($Bytes -ge 1KB) { '{0:N2} KB' -f ($Bytes / 1KB) }
    else                    { "$Bytes bytes" }
}

Get-ChildItem .\reports -File | Sort-Object Length -Descending | ForEach-Object {
    '{0,-16} {1}' -f $_.Name, (Format-FileSize $_.Length)
}

Output:

q3-deck.pptx     5.50 MB
sales-2026.csv   47.08 KB
notes.txt        812 bytes

Sorting on Length before formatting matters, because sorting the text “5.50 MB” would put it in the wrong order. Here’s how Sort-Object sorts by a property.

Get the total size of several files

Pipe the files to Measure-Object with -Property Length and -Sum. It adds up the bytes and counts the files:

$sum = Get-ChildItem .\reports -File | Measure-Object -Property Length -Sum

"Files: $($sum.Count)"
"Total: {0:N0} bytes ({1:N2} MB)" -f $sum.Sum, ($sum.Sum / 1MB)

Output:

Files: 3
Total: 5,816,193 bytes (5.55 MB)

The -File switch skips subfolders such as archive. To include files in subfolders, add -Recurse, as in getting the size of a folder.

As a table, the numbers look different in each version:

Get-ChildItem .\reports -File | Measure-Object -Property Length -Sum -Maximum |
    Format-Table Count, Sum, Maximum

Output:

Count         Sum     Maximum
-----         ---     -------
    3 5816193.000 5767168.000

PowerShell Measure-Object file size sum in Windows PowerShell 5.1 — Measure-Object shows 5816193 without decimals (Windows PowerShell 5.1)

Windows PowerShell 5.1 prints 5816193, while PowerShell 7 prints 5816193.00. It’s the same [double] in both; only the table format differs. Measure-Object can also return the average and minimum.

Why does a folder show a size of 1?

Get-Item works on folders too, but a DirectoryInfo object has no Length property:

$item = Get-Item .\reports

"Length of a folder: $($item.Length)"
"Is a folder:        $($item.PSIsContainer)"

Output:

Length of a folder: 1
Is a folder:        True

The 1 isn’t a size. When an object has no Length, PowerShell falls back to its built-in Length for a single item, which is always 1. Check PSIsContainer, or use Get-ChildItem -File so folders never reach your math.

Get the current size of a file that changes

A FileInfo object keeps the size it read. If a log keeps growing after you call Get-Item, call Refresh() before you read Length again:

Set-Content .\reports\log.txt ('a' * 500) -NoNewline
$file = Get-Item .\reports\log.txt
Add-Content .\reports\log.txt ('x' * 100) -NoNewline

"Before Refresh(): $($file.Length)"
$file.Refresh()
"After Refresh():  $($file.Length)"

Output:

Before Refresh(): 500
After Refresh():  600