Back Up a Mac with Time Machine: Drive Size, Setup Steps, Backup Schedule and Restoring
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How we wrote this: A plain-English summary of Apple Support's Back up your Mac with Time Machine article, checked October 29, 2026. Menu names below are for macOS Ventura 13 or later.
Time Machine is the backup tool built into every Mac. With an external drive it backs up your apps, music, photos, email and documents automatically.
1. Pick a drive
- Size: Apple suggests at least twice your Mac's storage. For a Mac with 1TB, use a 2TB or larger backup disk.
- Connection: an external USB or Thunderbolt drive in the right port.
- Use it only for Time Machine. Apple says not to store other files on the backup disk. Advanced users can add a separate APFS volume for other files instead.
2. Set it up
- Apple menu → System Settings → General → Time Machine.
- Click Add Backup Disk (or the + button).
- Choose the drive and click Set Up Disk.
- Your Mac may offer to erase the drive for Time Machine.
- It may ask whether to claim existing backups from another computer.
- Turn on Encrypt Backup to protect it, and keep that password safe. You'll need it to restore.
The first backup starts right away. It can take a while, but you can keep working.
3. How often it backs up
Apple says Time Machine keeps:
| Backups | Kept for |
|---|---|
| Hourly | The past 24 hours |
| Daily | The past month |
| Weekly | All previous months |
When the disk fills up, the oldest backups are deleted. To change the frequency: Time Machine menu → Open Time Machine Settings → Options → Back up frequency. To back up right now, choose Back Up Now from the Time Machine menu in the menu bar.
Later backups are faster because only changed files are copied. Eject the disk (or shut down) before unplugging it. Backups resume automatically when you reconnect it.
4. Restoring
You can restore some or all files to the same Mac or a new one. Apple has a separate article on restoring from a Time Machine backup.
Make it a real backup plan
One local drive isn't enough on its own. Fire, theft or ransomware can take out both the Mac and the drive. Pair Time Machine with an off-site or cloud copy, following the 3-2-1 backup rule. Also turn on FileVault, and plug the drive into a surge protector or UPS.
On Windows? See Windows Backup.