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We all worry about hitting the limits of our Mac’s storage space. We need room for downloading new apps, installing updates, and storing our creative works. Here are the two quickest and most useful ways to see how much free space you have left.

How to Quickly Check Free Disk Space Using Finder

The most basic way to check free disk space on a Mac is by using Finder. Open a new Finder window by pressing Command+N or selecting File > New Finder Window in the menu bar. (You can also use a little-known shortcut to open one from anywhere.)

In the window that opens, click on the drive you’d like to check in the sidebar. At the bottom of the window, you will see how much space is left on the drive.

Free space displayed at the bottom of a Finder window on macOS Catalina

You’re looking for a line that reads something similar to “904 GB available,” but with a different number, depending on how much free space you actually have on the drive.

You can repeat this step with any drive connected to your Mac by clicking on the drive’s name in the Finder window sidebar. Once you only have a few gigabytes free, then it’s time to think about deleting things to make room for the system to function properly.

RELATED: How to Open Finder with a Keyboard Shortcut on Mac

How to See Detailed Disk Usage in “About This Mac”

Since Mac OS 10.7, Apple has also included a built-in tool to view both free disk space and detailed disk usage that can be accessed through the “About This Mac” window. Here’s how to see it.

First, click on the “Apple” menu in the upper-left corner of the screen and select “About This Mac.”

In the window that pops up, click on the “Storage” button. (Depending on your macOS version, this may look like a tab instead of a button).

You will see a window that lists available disk space for all of your storage drives, including hard drives, SSDs, and external USB drives. For each drive, macOS also breaks down storage by file type in a horizontal bar graph.

Checking free disk space in macOS Catalina

If you hover your mouse over the bar graph, macOS will label what each color means and how much space that class of files takes up.

Hover your mouse over the disk storage graph to see space by file type in macOS Catalina

If you want even more detailed information on which file types take up the most space, click the “Manage” button. The window that pops up includes a  “Recommendations” pane full of tools that allow you to free up disk space by cleaning up files that you might not need anymore, including automatically emptying your trash on a regular basis.

macOS Catalina tools that help manage disk space

In that same window, you can click on any one of the options in the sidebar to see a breakdown of disk usage by file type.

Application disk usage on macOS Catalina

This interface also lets you delete files that may be important, so be careful. But if you know what you’re doing, it can be a quick handy way to free up disk space in a pinch.

There are many other ways to free up disk space on a Mac, including using third-party utilities, removing duplicate files, and deleting temporary cache files. Cleaning up an overstuffed computer can be satisfying, so have fun!

RELATED: How to Free Up Disk Space on a Mac

Profile Photo for Benj Edwards Benj Edwards
Benj Edwards is a former Associate Editor for How-To Geek. Now, he is an AI and Machine Learning Reporter for Ars Technica. For over 15 years, he has written about technology and tech history for sites such as The Atlantic, Fast Company, PCMag, PCWorld, Macworld, Ars Technica, and Wired. In 2005, he created Vintage Computing and Gaming, a blog devoted to tech history. He also created The Culture of Tech podcast and regularly contributes to the Retronauts retrogaming podcast.
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