How do I find out the capacity of my hard drive?

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How do I find out the capacity of my hard drive

Quick answers

There are a few quick ways to find out the capacity of your hard drive:

  • Check File Explorer (Windows) or Finder (Mac) – The hard drive capacity will be listed under “Devices and Drives” or “This PC”
  • Check Disk Management (Windows) – Right click the Start menu and select “Disk Management”. The drive capacity will be listed there.
  • Check System Information (Windows) – Search for “System Information” and open it. Under “Components > Storage” the drive capacity will be listed.
  • Check About This Mac (Mac) – Click the Apple menu and select “About This Mac”. Click “Storage” and the capacity will be shown.

Checking File Explorer or Finder

The easiest way to find your hard drive’s capacity is by checking File Explorer on Windows or Finder on Mac. Here’s how:

On Windows

  1. Open File Explorer by clicking the folder icon in your taskbar or searching for it
  2. In the left pane, click “This PC”
  3. Under “Devices and Drives” your hard drive(s) will be listed with the capacity, used space and free space

For example, you may see:

Hard Drive (C:) – 465 GB total, 243 GB free of 232 GB

This tells you the total capacity of your C: drive is 465 GB.

On Mac

  1. Open Finder by clicking the smiling face icon in your dock
  2. In the left pane under “Devices” you will see your hard drive(s) listed
  3. The overview will show the drive name, format, capacity, used space and available space

For example, you may see:

Mac SSD – 465.7 GB capacity, 223.5 GB available

So your total drive capacity is 465.7 GB.

Using Disk Management in Windows

Disk Management provides more detailed storage information in Windows. To use it:

  1. Right click the Start menu and select “Disk Management”
  2. Your hard drive volumes will be listed
  3. The total size and used space will be shown for each drive

For example, your C: drive may show:

465 GB total, 232 GB free of 232 GB

Giving you the total 465 GB capacity.

How to Open Disk Management

If Disk Management isn’t in your right-click Start menu, here’s a couple other ways to open it:

  • Type “diskmgmt.msc” into the Run dialog box (Windows + R)
  • Search for “Create and format hard disk partitions” and open that Control Panel applet
  • Open the Start menu and search for “Disk Management”

Checking System Information in Windows

The System Information utility provides detailed specs about all your PC’s hardware components, including storage. To use it:

  1. Type “System Information” into the Windows search bar and open the app
  2. Click “Components” in the left pane
  3. Click “Storage” in the left pane
  4. Locate the Disk Drives section
  5. Your hard drive will be listed with its model, capacity and other details

For example, you may see something like:

WDC WD5000AAKX-085CA0 – 465.76 GB

Indicating a 465.76 GB capacity.

Other Ways to Open System Information

If you can’t find System Information, try these steps:

  • Type “msinfo32” into the Run dialog
  • Right click the Start menu and select “System Information”
  • From Control Panel, open the System applet

Checking About This Mac on Mac

Here’s how to find drive capacity details on a Mac:

  1. Click the Apple menu and select “About This Mac”
  2. Click “Storage”
  3. The overview will display your hard drive name, format, capacity, used space and available space

For example:

Mac SSD – 465.7 GB capacity, 223.5 GB available

Using Disk Utility on Mac

For more details, use the Disk Utility app:

  1. Open Finder
  2. Go to Applications > Utilities
  3. Open Disk Utility
  4. Select your hard drive in the left pane
  5. Click the Info button
  6. Detailed storage specs will be displayed, including capacity

Tips for Checking Drive Capacity

Here are some additional tips for getting hard drive capacity info:

  • To see used vs free space on Windows, check File Explorer or Disk Management
  • On Mac, About This Mac gives used/free space, or use Disk Utility
  • For external drives, unplug/replug in to refresh the status
  • Drive manufacturers calculate capacity differently than Windows/Mac
  • So the stated capacity from the vendor is higher than what shows in your OS

Why Hard Drive Capacity Differs

You may notice the capacity reported by Windows or Mac is less than the advertised capacity from the drive manufacturer. Why is this?

It mainly comes down to how drive capacity is calculated:

  • Hard drive vendors advertise capacity in decimal units (1000 bytes = 1 KB)
  • Windows and Mac calculate capacity in binary units (1024 bytes = 1 KB)

So a “500 GB” hard drive from a vendor may show up as “465 GB” in Windows. The actual byte capacity is the same, just calculated differently.

Decimal vs Binary Units

Capacity Decimal Binary
1 KB 1000 bytes 1024 bytes
1 MB 1000 KB 1024 KB
1 GB 1000 MB 1024 MB

Because of this difference, the reported capacity in Windows or Mac can be about 3-7% less than advertised. But it’s the same total number of bytes.

Other Factors Affecting Capacity

Aside from decimal vs binary units, here are some other reasons why the available capacity might be lower than expected:

  • The Windows or Mac operating system takes up space
  • Preinstalled software and recovery partitions use disk space
  • Formatting the drive reduces available capacity
  • Some space is reserved for system files and boot sectors

Generally, these factors can account for 5-20% of the total drive capacity being unavailable for your files.

What To Do if Capacity Seems Too Low

If the available capacity on your hard drive seems lower than it should be, a few things you can try:

  • Remove unnecessary files and programs to free up space
  • Use disk cleanup utilities to delete system files and temporary files
  • Uninstall apps and features you don’t use
  • Move files to external storage devices
  • Use storage optimization tools to find and delete large files

Recovering lost disk space can help gain back some of that missing drive capacity.

Conclusion

Finding your hard drive capacity in Windows or Mac is simple once you know where to check – in File Explorer, Finder, Disk Management or System Information. The total capacity might be slightly less than advertised due to how manufacturers calculate it differently than operating systems. Other factors like the OS, software, formatting and file storage can also account for missing drive space. But being able to view the total, used and available capacity will give you insight into your hard drive status.