How much free space should a Mac have?

How do I check how much free space I have?

1. Choose Apple menu > System Settings, then click General in the sidebar. You may need to scroll down.
2. Click Storage.
3. Read the bar at the top. It shows how much space is used and how much is available.

For a quick look while you work, open a Finder window and choose View > Show Status Bar. The bar at the bottom of the window shows the space available on that disk.

Why does free space matter?

A Mac uses its startup disk for more than your files. Here’s what Apple’s pages say about the space:

• Speed. In Apple’s guide to a Mac that runs slowly, the first cause listed is a startup disk without enough free disk space.
• Memory. When apps need more memory than the Mac has free, macOS moves some of it to the startup disk. Activity Monitor calls that space Swap Used.
• Updates. If the macOS installer says your Mac doesn’t have enough storage space, Apple’s answer is to free up space and try again.
• Housekeeping. When space is needed, macOS clears caches and logs that are safe to delete, such as interrupted downloads and staged updates.

How do I know if memory is using the disk?

Activity Monitor shows it.

1. Open Activity Monitor. It’s in Applications > Utilities, or search for it with Spotlight.
2. Click Memory.
3. Look at Swap Used at the bottom of the window, beside the Memory Pressure graph.

Swap Used is the space on your startup disk that macOS uses to move memory in and out of RAM. When memory pressure is yellow or red and Swap Used climbs, your Mac leans on the disk, and a nearly full disk leaves it less room.

So how much should I keep free?

Because Apple gives no figure, size it to what your Mac has to do:

1. Room for the next macOS update. Before you update, check Storage. If the installer asks for more space, free some and try again. Apple says Software Update can use less storage to download and install updates than other ways of installing macOS.
2. Room for your biggest regular job. If you import 12 GB of video at a time, or export a large project, keep well more than that free, so the job never fills the disk halfway through.
3. Room for memory. If you often see yellow memory pressure with Swap Used in gigabytes, leave extra space for it.

These signs mean it’s time to free up space:

How do I get more free space?

1. Empty the Trash. Files in the Trash take up space until you empty it.
2. Delete large files you don’t need. In Storage, click the info button (ⓘ) next to Documents, then click Large Files.
3. Move files you want to keep to an external drive.
4. Turn on Storage’s recommendations: Store in iCloud, Optimize Storage and Empty Trash automatically.

“Your disk is almost full”: what to do first walks through each step. If an update still won’t fit, starting up in safe mode clears some system caches, which Apple says can free enough space to install it.

Questions people also ask

Is 10% free space enough on a Mac?

Apple doesn’t set a percentage. On a 1 TB Mac, 10% is about 100 GB; on a 256 GB Mac, it’s about 25 GB. What matters is whether updates install and your Mac stays responsive, so check Storage before each macOS update.

Does a nearly full SSD slow down a Mac?

It can. Apple lists a startup disk without enough free space as a cause of a Mac running slowly, and macOS needs free space for swap and its own housekeeping.

Does iCloud storage count as free space on my Mac?

No. An iCloud plan is space in iCloud. Store in iCloud moves files there and keeps recent ones on your Mac when space is needed, which is what frees space on the Mac itself.