How to Check Disk Space on Mac:
5 Free Methods (2025)

Method 1 Check Mac Disk Space via About This Mac

About This Mac Storage Settings delivers the most visual mac check disk space overview in macOS, displaying used and available space as a color-coded bar chart with per-category breakdowns. The navigation path differs by macOS version.

The color bar chart assigns a distinct color to each storage category. Hover over any segment to see the exact GB consumed. Storage categories displayed in Storage Settings include:

• Apps — all installed applications and their support files
• System Data — caches, logs, and Time Machine local snapshots (typically 10 to 25 GB)
• Documents — user-created files including PDFs, spreadsheets, and presentations
• iCloud Drive — files stored in iCloud that may or may not be available locally
• Other — files macOS cannot categorize, including virtual machine images and large archives

System Data is the most misunderstood category. macOS accumulates cache files, system logs, and local Time Machine snapshots inside System Data invisibly. Typical size ranges from 10 GB on a recently set-up Mac to 25 GB or more on a system used for two or more years.

What Is the Startup Disk and Why Is It Almost Full?

The startup disk on a Mac is Macintosh HD — the primary APFS (Apple File System) volume that macOS boots from. Finder labels it "Macintosh HD" by default, and Disk Utility lists it at the top of the volume group.

The "startup disk almost full" warning appears in macOS when free space drops below approximately 10 percent of total capacity. On a 256 GB Mac, this threshold triggers at roughly 25 GB remaining. System Data (caches, logs, Time Machine snapshots) is the most common cause, consuming 10 to 25 GB on typical systems. The free cleanup checklist in Method 7 covers six steps with concrete GB recovery ranges per action.

Method 2 Check Mac Storage via Disk Utility

Disk Utility returns raw capacity figures for the Macintosh HD volume — total size, used bytes, and available bytes — without the category breakdown provided by About This Mac. Disk Utility is the preferred source when verifying exact formatted capacity after an erase or reinstall.

1. Press Command + Space to open Spotlight.
2. Type Disk Utility and press Return.
3. Select Macintosh HD in the left sidebar.
4. Read the capacity, used, and available figures displayed at the bottom of the window.

Method 3 Check Mac Disk Space in Terminal

Terminal returns human-readable disk space data via the df -h command, reaching the same APFS volumes as Disk Utility but in a scriptable, copyable text format unavailable in any GUI tool. Neither MacPaw nor Setapp covers this method with step-by-step depth — it is the primary differentiation of this guide.

1. Press Command + Space, type Terminal, and press Return.
2. Run the command below and press Return.
3. Read the /System/Volumes/Data line — this is your user-accessible storage.

$ df -h

Filesystem        Size   Used  Avail Capacity  Mounted on
/dev/disk3s1s1   460Gi  14Gi  214Gi    7%     /
/dev/disk3s6     460Gi  5.0Gi 214Gi    3%     /System/Volumes/VM
/dev/disk3s5     460Gi  214Gi 214Gi   50%     /System/Volumes/Data
/dev/disk3s2     460Gi  524Mi 214Gi    1%     /System/Volumes/Preboot

# ↑ Read THIS line for your startup disk free space
# Avail = free space  |  Capacity = % used  |  Size = total

To check how much space a specific folder consumes, use du -sh followed by the folder path. For example:

$ du -sh ~/Downloads
18G    /Users/yourname/Downloads

$ du -sh ~/Library/Application\ Support/MobileSync/Backup
 9G    /Users/yourname/Library/Application Support/MobileSync/Backup

Method 4 Best Apps to Check & Manage Disk Space on Mac

Three genuinely free tools cover disk space monitoring without cost: Stats (menu bar), GrandPerspective (treemap), and Disk Inventory X (treemap alternative). Five additional apps — iStat Menus, CleanMyMac, CloudMounter, Unclutter, and Get Backup Pro — extend disk management to monitoring, cleanup, cloud mounting, file organization, and backup. The table below covers all eight with pricing and disk-relevance context.

Green rows = free/open-source. Orange rows = paid apps. All available at torrentmac.net unless noted.

How to set up Stats in the menu bar (2 steps):

1. Download Stats v2.11.23 from torrentmac.net or mac-stats.com. The Stats GitHub repository (github.com/exelban/stats) has accumulated more than 38,000 stars, confirming active community maintenance.
2. Open Stats.app, click the menu bar icon, select Preferences → Disk, and enable the disk usage widget. Stats displays used and free gigabytes in real time next to the clock.

GrandPerspective v3.6.1 (released December 2025, licensed under GNU GPL) visualizes every file on the startup disk as a colored rectangle scaled to file size. GrandPerspective serves as a free alternative to DaisyDisk for users who need a treemap without paying $9.99.

How Each App Helps With Mac Disk Space

• iStat Menus 7 — displays disk read/write speeds and used/free GB directly in the menu bar with 28-day history graphs. Bjango (developer) prices it at $11.99 one-time; it monitors disk activity in real time alongside CPU, GPU, and RAM.
• CleanMyMac (MacPaw) — scans the startup disk for system junk, mail attachments, language files, and large unused files. The Space Lens feature renders a treemap of the entire Macintosh HD volume, identifying the largest space consumers in one scan. Subscription starts at $29.95 per year.
• CloudMounter (Eltima) — mounts Google Drive, Dropbox, Amazon S3, OneDrive, and other cloud services as local Finder volumes. Files remain in the cloud and consume zero SSD space locally, effectively extending available startup disk capacity without deleting anything. Priced at $29.99 one-time.
• Unclutter — provides a slide-down panel for clipboard history, notes, and temporary file storage. Keeping Desktop and Downloads organized through Unclutter reduces the volume of large files accumulating on the startup disk. Priced at $9.99 one-time.
• Get Backup Pro (Belight Software) — creates incremental and versioned backups to external drives or NAS. Offloading archived project files and old media to an external drive via Get Backup Pro directly reduces startup disk usage. Priced at $19.99 one-time.

Method 5 Check Scratch Disk Space on Mac

A scratch disk is a temporary workspace that creative applications (Adobe Photoshop, Premiere Pro, DaVinci Resolve) write to when available RAM is insufficient for active operations. The startup disk (Macintosh HD) serves as the default scratch disk unless manually changed. Neither MacPaw nor Setapp covers this keyword cluster.

To check and change the scratch disk in Photoshop:

1. Open Photoshop.
2. Go to Photoshop menu → Preferences → Scratch Disks.
3. The Active column shows which volume Photoshop uses. Available space appears next to the volume name.
4. Check or uncheck volumes to reassign the scratch disk to a drive with more free space, then restart Photoshop.

iCloud iCloud Storage vs. Mac Disk Space — What Is the Difference?

Mac disk space and iCloud storage are two separate quotas. The startup disk (Macintosh HD) holds local SSD capacity (256 GB to 2 TB depending on Mac model). iCloud storage (5 GB free, expandable via iCloud+) is a remote quota stored on Apple servers — it has no direct relationship to SSD size.

iCloud Drive Desktop and Documents syncing is the primary cause of Macs appearing to have less storage than their SSD rating. When macOS offloads Desktop and Documents files to iCloud, those files display a cloud icon in Finder and count against iCloud quota, not local storage.

To check iCloud quota separately from local disk space:

1. Open System Settings (macOS Ventura or later) or System Preferences (Monterey).
2. Click Apple ID → iCloud.
3. The iCloud storage bar at the top shows used and available iCloud quota.

To disable Desktop and Documents offloading: go to System Settings → Apple ID → iCloud → iCloud Drive → Options, then uncheck Desktop and Documents Folders. Google Drive offers 15 GB free as an alternative syncing solution.

Method 7 How to Free Up Disk Space on Mac for Free

Six free actions recover the most local storage on a typical Mac:

• Empty Trash Right-click the Trash icon in the Dock and select Empty Trash. macOS retains deleted files until explicitly emptied.
  0.5 – 10+ GB
• Clear Downloads folder Open Finder → Downloads, sort by size (View → Show View Options → check Size), and delete large files. Installer .dmg files frequently accumulate here.
  1 – 20+ GB
• Remove iOS backups Open Finder → Go → Go to Folder, paste ~/Library/Application Support/MobileSync/Backup, and delete outdated device backup folders.
  3 – 15 GB
• Clear browser cache In Safari: Develop menu → Empty Caches. In Chrome: Settings → Privacy and security → Clear browsing data → Cached images and files.
  1 – 5 GB
• Delete language files via Monolingual Monolingual (free, open-source) removes unused language resources from system apps. Download from sourceforge.net/projects/monolingual.
  0.5 – 2 GB
• Remove large unused apps Open Finder → Applications, right-click any app, select Get Info to see exact size, then drag unused apps to Trash.
  200 MB – 5 GB

Done Conclusion

Mac check disk space works through five methods, each suited to a different use case. About This Mac Storage Settings provides the clearest category overview for everyday monitoring. Disk Utility returns raw capacity figures for technical verification. Terminal's df -h command delivers scriptable, precise output for power users. Free third-party apps (Stats, GrandPerspective) extend monitoring to the menu bar and treemap visualizations without cost.

Two points prevent the most common disk space confusion: iCloud Drive Desktop and Documents offloading reduces apparent local storage without changing SSD capacity; and the 5 to 15 GB gap between About This Mac and Disk Utility figures is normal APFS purgeable-space accounting, not data loss.

FAQ Frequently Asked Questions