Levo guides · Disk space

How to check storage on a Mac

Open System Settings › General › Storage. It shows how much of your disk is used, split into categories, and how much is free. Finder, Disk Utility and Terminal show the same disk from other angles, and their numbers rarely match exactly.

Where	What it shows	Best for
System Settings › General › Storage	Used space by category, and what macOS can free	A quick look
Finder › Get Info on the disk	Capacity, available and used, with purgeable space counted as available	The number Finder uses for copying and saving
Disk Utility	Capacity, used, and the APFS container and volumes	Seeing how the disk is divided
`df` in Terminal	Raw free blocks, without purgeable space	The strictest number
`du` in Terminal	The size of one folder	Finding what is big

Storage settings

Choose Apple menu › System Settings.
Click General, then Storage.
Wait for the bar to finish calculating. The categories load one by one, so the first picture is incomplete.
Click the ⓘ next to a category to see what is in it. System Data has no such button, because macOS doesn’t break it down.

The bar is useful for proportions: how much is Applications, Documents, Photos and System Data. It is not a way to find which folder is big. For that, see How to find large files on a Mac.

Finder

Open Finder, then Go › Computer (⇧⌘C).
Select your disk, usually Macintosh HD, and press ⌘I.
Read Capacity, Available and Used.

Available includes purgeable space: caches and files macOS will delete on its own if something needs room. That is why Finder can say you have 40 GB more than df does.

Disk Utility

Open Disk Utility from Applications › Utilities.
Choose View › Show All Devices, then select the volume called Macintosh HD - Data.
Read the used and available figures in the panel on the right.

On an APFS disk, volumes share one container, so the free space is the same for all of them. The system volume, the Data volume, Preboot, Recovery and VM are all drawing on it. That is why Macintosh HD alone can look tiny and the Data volume large.

Terminal

For the strictest answer:

df -h /System/Volumes/Data

For the size of your biggest folders in your home folder, sorted:

du -sh ~/* 2>/dev/null | sort -h | tail -15

For the APFS layout, including each volume’s share:

diskutil apfs list

Why the numbers don’t match

Purgeable space. Finder and Storage settings count it as free, df doesn’t. See Purgeable space vs System Data.
Decimal against binary. macOS counts a gigabyte as one billion bytes. Some tools use 1,073,741,824, so the same disk looks about 7 percent smaller.
Local snapshots. Time Machine keeps snapshots on the disk until it needs the room. They sit in System Data, and the Storage bar may lag behind a deletion.
The calculation is slow. Right after a big change, Storage settings can show old numbers for a few minutes.

If a category looks too big, System Data, macOS and Other Volumes in Storage settings explains what each one holds.

How Levo does it

Levo sits in the menubar and shows the disk as a meter in its popover, so you check storage with one click and nothing to open. It keeps a live index of your home folder, hidden folders and Library included, so it doesn’t rescan each time you look.

Under the meter, Ready to free lists what is taking space and can go, grouped by kind, each with a size and a reason. Levo splits Caches, Developer, Mail and Messages out of System Data, so what is left under that label is smaller than in Storage settings. The free-space figure counts purgeable space the way Finder does, which is explained in Free space looks different in Finder.

You can also set a limit, and Levo notifies you when free space drops below it, with the answer ready.

FAQ

Why does Finder show more free space than Terminal?

Finder counts purgeable space as available, because macOS deletes it automatically when something needs room. The df command counts only blocks that are free right now, so its number is lower.

How do I check storage on a Mac from Terminal?

Run df -h /System/Volumes/Data for the disk, and du -sh on a folder for its size. Both are built in, and neither changes anything.

Why does Storage settings take so long to load?

macOS calculates each category separately, and System Data last. On a large disk this can take a few minutes, and the numbers can be stale right after you delete files.

How much free space should I keep?

Keep enough that updates and the swap file can grow, a tenth of the disk or at least 20 GB is a sensible floor. Below that, apps start to slow down and macOS updates can fail.