If you want to back up your Mac with Time Machine, the good news is that Apple has already built everything you need into macOS. All you need is an external drive and about ten minutes. Once it is set up, Time Machine quietly saves hourly copies of your files, so a failed update, a spilled coffee or an accidental deletion becomes an inconvenience instead of a disaster. This guide shows you which drive to buy, how to set Time Machine up, how it keeps your backups, and how to restore files when you need them.
What is Time Machine?
Time Machine is Apple’s built-in backup tool for the Mac. After the first full backup, it copies only the files that changed, so later backups are small and quick. Because it keeps older versions, you can go back to how a document looked yesterday, last week or last month, not just to the latest copy.
Time Machine is not a magic shield, though. It protects you from loss, not from every kind of problem, so it works best as part of a simple routine. We will cover that routine near the end of this guide.
What you need before you start
- An external drive. A USB or Thunderbolt drive works well. Apple recommends a drive with at least twice the storage capacity of your Mac, so a 1 TB Mac needs about a 2 TB drive.
- A free port or adapter. Many newer Macs only have USB-C or Thunderbolt ports, so check whether your drive needs an adapter.
- A drive used only for backups. Keep personal files and photos on a different drive, or Time Machine will have less room to work with.
According to Apple Support, Time Machine will tell you if it needs more space, so a drive that is slightly too small will not break anything. It will just keep fewer old versions.
How to set up Time Machine on your Mac
These steps are for macOS Ventura 13 and later, including the latest versions. Older macOS versions use System Preferences instead of System Settings, but the idea is the same.
- Connect your external drive to the Mac.
- Click the Apple menu and choose System Settings.
- Click General in the sidebar, then click Time Machine.
- Click Add Backup Disk (or the Add button).
- Select your drive and click Set Up Disk.
Prompts you may see during setup
- Erase the drive: Your Mac may ask to erase the disk so it can use it for Time Machine. Make sure nothing important is on it, then confirm.
- Claim existing backups: If the drive already holds backups from another computer, you can claim them so they become part of this Mac’s history.
- Encrypt Backup: Turn this on if your Mac contains private data. You will create a backup password, and you will need it later to restore files. Store it somewhere safe, because without it the backup cannot be opened.
Backups start straight away after setup. The first backup can take a long time, especially on a large Mac, but you can keep working while it runs.
How Time Machine keeps your backups
Apple describes a simple schedule that keeps more detail for recent files and less for older ones:
| Backup type | How long it is kept |
|---|---|
| Hourly backups | For the past 24 hours |
| Daily backups | For the past month |
| Weekly backups | For all earlier months, until the disk is full |
When the backup disk fills up, Time Machine deletes the oldest backups first to make room for new ones. That is why a larger drive gives you a longer history.
How to back up manually and change the schedule
Back up right now
Click the Time Machine icon in the menu bar and choose Back Up Now. This is useful just before you install a big update or hand your Mac in for service. If you do not see the icon, you can turn on the Time Machine status in the menu bar from System Settings.
Change how often backups run
On macOS Ventura 13 and later, open the Time Machine menu, choose Time Machine Settings, click Options, and pick a value from Back up frequency. Most people are fine with the default of hourly backups.
Stop, skip or check progress
From the same menu bar icon you can stop a backup, skip one, and see when the last successful backup was made. Check this date now and then. A backup that has not run for weeks is the most common reason people find out too late that they were not protected.
How to restore files from Time Machine
- Open the folder where the file used to be, or open the app you used to create it.
- Click the Time Machine icon in the menu bar and choose Browse Time Machine Backups.
- Use the timeline or the arrows to go back to a date when the file still existed.
- Select the file or folder and click Restore.
The file returns to its original location. You can also restore to a different Mac, which is handy when you buy a new computer and want to move your data across.
Disconnect the drive the right way
Before you unplug the backup drive, eject it from Finder or shut the Mac down first. Pulling the cable during a backup can damage the backup or the drive. When you reconnect the drive later, Time Machine resumes the schedule automatically.
Smart backup habits that go beyond Time Machine
- Follow the 3-2-1 idea. Keep three copies of important data, on two different kinds of storage, with one copy somewhere else, such as cloud storage or a drive kept at another location.
- Back up before updates. If a macOS update goes wrong, a fresh backup is your safety net. This is especially useful if you see problems like the ones in our guide on what to do when you cannot update to macOS 27.
- Back up before troubleshooting. Fixes for slowdowns, such as those in Mac running slow after an update, sometimes involve resetting or reinstalling things. Take a backup first.
- Test your restore. Once a month, restore one unimportant file to confirm that the backup really works.
- Keep the drive healthy. Hard drives wear out, so replace the backup drive every few years.
Common Time Machine problems and fixes
Time Machine says the disk is full
Remember that Time Machine removes the oldest backups automatically. If it still complains, the drive is too small for your Mac, or the drive also holds other large files. Use a larger drive, or remove the extra files.
The backup drive does not show up
Try a different cable or port first. Then open Disk Utility and see whether the drive appears there. If it does not, the drive or its cable may have failed. If your Mac does not start at all, our guide to fixing a Mac startup problem can help before you restore.
The first backup takes forever
This is normal. The first backup copies everything, and large photo or video libraries take hours. Leave the Mac plugged in and connected to power. Later backups copy only the changes and finish much faster.
Backup is stuck or keeps failing
Restart the Mac, reconnect the drive and run Back Up Now again. If the problem continues, check the drive in Disk Utility with First Aid, and consider switching to a different backup disk.
Frequently Asked Questions
How big should my Time Machine drive be?
Apple suggests a drive with at least twice the capacity of your Mac. For example, a Mac with 1 TB of storage works best with a 2 TB backup drive.
Does Time Machine back up everything on my Mac?
Time Machine backs up your files, apps and settings so you can restore them. It is meant for recovery of your data and system, but it is not a complete clone for every situation, so keep important files in more than one place.
Can I use my Mac while Time Machine is backing up?
Yes. Backups run in the background, and you can keep using your Mac. The first backup may slow things slightly because it copies everything.
How often does Time Machine back up?
By default it makes hourly backups while the drive is connected. You can change the frequency in the Time Machine options on macOS Ventura 13 and later.
Do I need to encrypt my Time Machine backup?
It is a good idea if your Mac holds personal, work or financial data, or if you carry the drive around. Just remember that you need the backup password to restore your files.
Conclusion
Setting up Time Machine takes only a few minutes: connect a drive, open System Settings > General > Time Machine, click Add Backup Disk, and choose whether to encrypt it. After that, your Mac saves hourly, daily and weekly versions automatically. Check the date of the last backup from time to time, test a restore now and then, and keep one extra copy of your most important files elsewhere. Do that, and you can update, experiment and troubleshoot your Mac without worry.
