The fastest way to see how much space you have left
Open the Apple menu in the top-left corner and select About This Mac. Click the Storage tab. You will see a colored bar showing how much of your drive is used, how much is free, and what types of files are taking up the most room — photos, apps, documents, and so on. This takes about 10 seconds and tells you whether you have a real problem or just need to delete a few things.
If the bar is mostly full (the free space is a thin line), your Mac will slow down noticeably. If you have less than 10 percent of your drive free, you should start removing files or moving them to external storage. The Storage tab also shows you which apps and files are largest, so you know where to start.
Key Takeaways
- The Storage tab in About This Mac shows your total space, how much is free, and what types of files are using the most room.
- You can click on any category in the Storage tab to see individual files ranked by size, starting with the largest.
- The Finder's Get Info window shows the exact size of a single file or folder, useful for deciding what to delete.
- If free space drops below 10 percent of your total drive, your Mac will run slowly and you should move or delete files.
Drilling down into what's using your storage
The Storage tab shows you categories like Photos, Applications, Documents, and Other. Click on any category to see the individual files inside it, sorted from largest to smallest. For example, clicking Photos will show you every photo library on your Mac, and you can see exactly how many gigabytes each one takes up.
This is the fastest way to find the biggest space-wasters. A single video file or old photo library often takes up 20 or 30 gigabytes without you realizing it. Once you know which files are largest, you can decide whether to delete them, move them to an external drive, or keep them where they are.
Using Finder to check individual files and folders
If you want to know the exact size of a single file or folder, open Finder and right-click on it. Select Get Info from the menu. A window will open showing the file size in both gigabytes and bytes. This is useful when you are deciding whether a specific folder — like your Downloads folder or a project folder — is worth keeping or moving.
You can also use Get Info to see how old a file is and when it was last opened. Files you have not touched in years are often safe to delete or archive. Combine this with the Storage tab to get a complete picture: the Storage tab shows you the biggest categories, and Get Info lets you zoom in on specific files.
Understanding the "Other" category and system files
The Storage tab shows a category called Other, which often takes up several gigabytes. This includes system files, caches, temporary files, and things macOS needs to run. You should not delete these files directly — your Mac needs them. However, you can free up some of this space by emptying your trash, clearing browser caches, and removing old language packs you do not use.
If Other is taking up more than 20 percent of your drive, your Mac has accumulated a lot of temporary junk. Restarting your Mac will clear some of this automatically. You can also go to System Settings, click General, then Storage, and look for options to remove old files or optimize storage.
Moving files to external storage instead of deleting them
Before you delete anything, consider moving it to an external drive instead. Connect an external drive to your Mac, then open Finder. Drag files or folders from your Mac to the external drive to copy them. Once the copy is complete, you can delete the originals from your Mac to free up space. This way you keep the files but get the storage room back.
External drives are cheap — a 2-terabyte drive costs less than $50 — and they are much faster than cloud storage for moving large files. If you have photos, videos, or old projects you want to keep but do not use often, an external drive is the best place for them. Just make sure to keep the drive in a safe place and test it occasionally to confirm the files are still readable.
Checking storage on external drives and USB devices
To see how much space is free on an external drive or USB stick, connect it to your Mac and open Finder. Click on the device name in the sidebar on the left. At the bottom of the Finder window, you will see how much space is used and how much is free. You can also right-click on the device and select Get Info to see the same information in a detailed window.
External drives fill up just like your Mac's internal drive, so check them regularly if you use them to store files. If an external drive is full, you will not be able to copy new files to it. Move old files off the external drive to another location, or delete files you no longer need, to make room for new ones.
When to worry about running out of space
Your Mac needs some free space to run smoothly — at least 10 to 15 percent of your total drive. If you have a 500-gigabyte drive, that means keeping at least 50 gigabytes free. When free space drops below this, your Mac slows down because it cannot create temporary files and cannot run maintenance tasks properly. You may also see warnings that your disk is almost full.
If you are consistently running out of space, you have three options: delete files you do not need, move files to external storage, or upgrade to a larger internal drive. For most people, moving old photos and videos to an external drive solves the problem. If you take a lot of photos or videos, or work with large files like video editing projects, you may need to upgrade your drive eventually.
Frequently Asked Questions
Why does my Mac show less free space than I think I should have?
Your Mac reserves space for system files, caches, and temporary files that you cannot see in Finder. The "Other" category in Storage includes these hidden files. Restarting your Mac clears some temporary files and may free up a few gigabytes. If you want more space, move large files to external storage or delete files you no longer use.
Can I delete files from the Other category to free up space?
No — the Other category contains system files your Mac needs to run. Deleting them can break your Mac. Instead, empty your trash, clear browser caches in System Settings, and remove old language packs. These actions are safe and can free up a few gigabytes without damaging your system.
What is the difference between storage shown in About This Mac and storage shown in Finder?
They show the same information, just in different ways. About This Mac gives you a visual overview with categories. Finder shows you the raw numbers for a specific drive or folder. Use About This Mac to see the big picture, and use Finder's Get Info for details about individual files.
How often should I check my disk space?
Check your storage once a month if you take photos or videos regularly, or once every few months if you do not. If you see free space dropping below 20 percent, start moving or deleting files. The sooner you act, the easier it is — waiting until your drive is completely full makes your Mac very slow.