How to Find Out How Much Space iPhone Backups Are Using on Your Mac (2026)

iPhone backups stored on your Mac can quietly grow to tens of gigabytes, especially if you back up multiple devices or have years of old backups sitting around. If you have ever wondered exactly how much space iPhone backups are using on your Mac, there are three reliable ways to find out — each giving you a slightly different level of detail. Here is how to check, what the numbers mean, and how to safely reclaim the space if you need it.

Where Mac Stores iPhone Backups

When you back up an iPhone or iPad over USB to a Mac, iTunes (macOS Mojave and earlier) or Finder (macOS Catalina and later) stores the backup in a fixed location:

~/Library/Application Support/MobileSync/Backup/

Each backup lives in its own folder named with a long alphanumeric device identifier. A single folder represents a complete backup of one device at the most recent point in time. Finder keeps only the latest backup per device by default, but if you have backed up multiple iPhones, iPads, or iPods, you will have multiple folders here.

This path is hidden by default in Finder. To open it directly, press Command + Shift + G in Finder and paste the path above.

Method 1: Check iPhone Backup Size in Finder With Get Info

This is the most precise method because it measures the actual folder size on disk rather than an estimate.

1. Open Finder and press Command + Shift + G.
2. Type ~/Library/Application Support/MobileSync/Backup and press Return.
3. You will see one or more folders with long hex names. To measure all backups at once, press Command + A to select everything.
4. Press Command + Option + I to open a combined Get Info window. The "Size" line shows the total on-disk size of all selected folders.
5. To check a single backup, click one folder, then press Command + I. macOS will count every file inside and report the exact byte count.

Note that "Size" and "Size on disk" are often slightly different — "Size on disk" reflects filesystem block allocation and is the number that matters for your free space.

Method 2: Check Backup Storage in About This Mac (or System Settings)

Apple's built-in storage overview gives a high-level breakdown but is less granular. On macOS Ventura 13 and later, this view has moved into System Settings.

1. Click the Apple menu () and choose System Settings (macOS Ventura and later) or About This Mac (Monterey and earlier).
2. On Ventura or later: go to General > Storage.
3. On Monterey or earlier: click the Storage tab, then click Manage.
4. Look for the iOS Files or iPhone Backups category in the sidebar. macOS groups all device backups under this label and shows the combined size.

This view gives a quick overview, but it can take a minute to calculate and sometimes lags behind the real on-disk size. For an accurate number, Method 1 or Method 3 is more reliable.

Method 3: See Per-Backup Size in Manage Backups

If you want to see the size of each individual device backup and decide which ones to delete, the Manage Backups dialog is the right place.

1. Connect or have previously connected your iPhone so that a backup exists.
2. Open Finder (macOS Catalina and later) or iTunes (Mojave and earlier).
3. In Finder, click your device in the sidebar, then hold Control and click in the backup section to find Manage Backups. Alternatively, open Finder, go to the menu bar, click Finder > Manage Backups. (This option appears in the menu only when a backup exists.)
4. A window lists each backup by device name, date, and size. This is the clearest view of which backup is taking the most space.
5. To delete an old or unneeded backup, right-click it and choose Delete Backup. Confirm when prompted. Deletion is permanent and cannot be undone.

Check Backup Size From Terminal

If you prefer the command line, du gives you an exact measurement in a single command:

du -sh ~/Library/Application\ Support/MobileSync/Backup/

To see each backup folder's size individually:

du -sh ~/Library/Application\ Support/MobileSync/Backup/*/

The -s flag summarizes each argument rather than listing every file, and -h prints human-readable units (GB, MB). This is the fastest way to get an accurate number without opening any windows.

Visualize Backup Folders With Crumb

If you have multiple device backups and want to see at a glance which one is the biggest, Crumb's disk visualization treemap can help. Open Crumb, switch to the Visualize tab, and navigate into ~/Library/Application Support/MobileSync/Backup/. Each backup folder renders as a proportional block — larger folders appear larger on screen — so you can immediately see which device backup is consuming the most space without doing any mental math on file listings.

Crumb also surfaces the MobileSync folder in its whole-Mac audit if it is one of your largest directories, which is useful if you forgot backup storage was growing in the background.

Is It Safe to Delete iPhone Backups?

Deleting a backup removes your ability to restore that device to its backed-up state. Before you delete:

• Verify iCloud Backup is enabled if you want an alternative. Open Settings on your iPhone, tap your name, then iCloud > iCloud Backup.
• Do not delete the most recent backup for a device you still use unless you are certain iCloud Backup is active and current.
• Old devices you no longer own are safe candidates — there is no device to restore.
• Deletion through Manage Backups is immediate and permanent. There is no Trash step.

Manually deleting files from ~/Library/Application Support/MobileSync/Backup/ in Finder is not recommended. The folder structure inside each backup is not human-readable, and partial deletion can leave orphaned data that macOS still counts as used space. Always use Manage Backups or iTunes/Finder's built-in deletion UI.

How to Prevent Backups From Growing Unnoticed

• After upgrading or replacing a device, open Manage Backups and delete the old device's backup.
• If you switch to iCloud Backup, disable local backups in Finder to stop new local copies from being created.
• Check ~/Library/Application Support/MobileSync/Backup/ periodically — a quick du -sh in Terminal takes two seconds.

Summary

Checking how much space iPhone backups use on your Mac is straightforward once you know where to look. Finder's Get Info gives you the most accurate on-disk number, Manage Backups shows per-device detail and lets you delete directly, and the Terminal du command is the fastest one-liner for the same information. If you want a visual overview of where your storage is going across your whole Mac, download Crumb and use the treemap to spot large backup folders alongside everything else competing for your disk space.