Maintenance procedure · Written to ASD-STE100 Issue 9 · Formatted to ANSI Z535

Set Up a Time Machine Backup on a Mac

macOS Ventura 13 and later — choose an external disk, set Time Machine up in System Settings, and prove the backup can actually give a file back
ApplicabilityAny Mac running macOS Ventura 13 or later, backing up to an external USB or Thunderbolt disk connected directly to the Mac. Checked against Apple's documentation on 2026-07-29, when the current Mac User Guide was published for macOS Tahoe 26 and Apple's Time Machine support article carried a published date of 6 July 2026. The network destinations Apple also supports — a shared Mac, a NAS device, an AirPort Time Capsule — are named here but not instructed.
Task timeat least 20 min to 1 hr 9 min (40 of 41 steps estimated) editorial estimate, not a measurement
PersonnelOne
Revisionv1 · 2026-07-29
BEFORE YOU BEGIN

Before you begin. This procedure is general reference information, not professional advice. Equipment varies by manufacturer, model, and year. Always follow the documentation supplied with your equipment — where it differs from this page, follow the manufacturer. Verify that you have the tools, the working conditions, and the ability to do this task safely. If anything is unclear, if the equipment is damaged, or if the task exceeds your experience, stop and use a qualified professional. You are responsible for your own safety and for the outcome. This site accepts no liability for any loss, damage, or injury arising from the use of this information.

Specifications marked unverified could not be traced to a manufacturer source. Do not rely on them — obtain the value from your equipment documentation.

Summary

Time Machine is the backup built into every Mac, and it is one of the few pieces of software that is genuinely finished: you plug in an external drive, answer two or three questions, and it keeps hourly, daily and weekly copies of your files from then on. The part people skip is the last part. A backup nobody has ever restored from is a hope, not a backup, so this page ends by walking you through pulling one real file back out of it.

It is written against Apple's own documentation as it stood on 29 July 2026, for macOS Ventura 13 and later, which is where Time Machine moved into System Settings. Two things this page will not do: it will not tell you which drive to buy, and it will not invent a way to recover a lost encryption password, because Apple does not document one. It does tell you the disk size Apple asks for, what Time Machine leaves out of the backup, and the exact point where the answer stops being ours and starts being Apple Support's. Every step traces to an Apple support article or a Mac User Guide topic, and both are linked in the sources.

Safety

NOTICE

READ THE macOS VERSION ON YOUR MAC FIRST.
Menu names change with a macOS update. This page follows the Apple documentation for macOS Ventura 13 and later.

NOTICE

A TIME MACHINE BACKUP IS NOT A FULL COPY OF macOS.
Time Machine does not copy the system files or the apps from the macOS installation. For a full recovery, you must install macOS again first.

Necessary equipment

ItemNote
Mac computerThe steps apply to macOS Ventura 13 and later.
External diskUse this disk only for the Time Machine backups.
USB-C cable or Thunderbolt cableThe cable must fit a port on your Mac.
Pen and paperMake a record of the macOS version and the backup password.

Find the macOS version

Estimated 2 min

NOTEApple moved the Time Machine controls from System Preferences to System Settings at macOS Ventura 13. The menu names on an earlier macOS are different.
  1. Select the Apple menu at the corner of the screen.
    <1m
  2. Select System Settings.
    • The name on an earlier macOS is System Preferences.
    • If you see System Preferences, the steps on this page do not apply to your Mac.
    <1m
  3. Select General in the sidebar.
    <1m
  4. Select About.
    <1m
  5. Read the macOS name and the macOS version.
    • macOS Ventura is version 13.
    • Each later macOS has a higher version.
    <1m
  6. Make a record of the macOS name and the macOS version on paper.
    • Give these two values to each person who helps you with a backup problem.
    <1m

Prepare the external disk

Estimated 4 min to 36 min

NOTETime Machine reserves the full volume. Files that you keep on the backup disk reduce the space for the backups.
Backup disk size that Apple gives as a minimum
Manufacturer or standard verified
Two times the storage capacity of your Mac

Source: Back up your Mac with Time Machine · tier 1 · accessed 2026-07-29

Disk size and disk model for your Mac
Unverified — do not rely on this value
CONSULT THE DISK MANUFACTURER AND THE APPLE DOCUMENTATION IN THE SOURCES

No tier-1 source was found for this value. Take it from the documentation supplied with your equipment.

NOTICE

COPY THE FILES THAT YOU MUST KEEP TO A DIFFERENT DISK BEFORE YOU START.
The setup can erase the external disk. An erase removes all the files on that disk permanently.

  1. Examine the external disk for files that you must keep.
    • The setup can ask you to erase the disk.
    • An erase removes all the files on the disk permanently.
    1m
  2. If the disk contains files that you must keep, copy those files to a different disk.
    2m
  3. Read the storage capacity of your Mac on the About page.
    • Apple gives a minimum size for the backup disk of two times that capacity.
    • Apple gives a larger disk if Time Machine asks for more space.
    <1m
  4. Connect the external disk to a USB-C port or a Thunderbolt port on your Mac.
    • Do not use a disk with a Windows format.
    • Do not use an iPhone, an iPad or an iPod as a backup disk.
    <1m
  5. If the disk has a power switch, set the power switch to on.
    <1m

Add the backup disk to Time Machine

Estimated 6 min to 15 min

Time Machine backup password
Unverified — do not rely on this value
CHOOSE YOUR OWN PASSWORD AND KEEP A RECORD OF IT

No tier-1 source was found for this value. Take it from the documentation supplied with your equipment.

  1. Open System Settings.
    <1m
  2. Select General in the sidebar.
    <1m
  3. Select Time Machine.
    <1m
  4. Select Add Backup Disk.
    • If your Mac already has a backup disk, select the add button.
    <1m
  5. Select your external disk in the list.
    <1m
  6. Select Set Up Disk.
    <1m
  7. If your Mac asks you to erase the disk, select Erase.
    • An erase removes all the files on the disk permanently.
    • If the disk holds files that you must keep, select a different disk instead.
    1m
  8. If your Mac asks you to claim the backups from a different computer, read the question fully.
    • A claim makes those backups part of the backups for this Mac.
    • If you do not want that result, select a different disk.
    <1m
  9. In the new window, set the maximum space for the backups.
    <1m
NOTICE

MAKE A RECORD OF THE BACKUP PASSWORD BEFORE YOU CONTINUE.
Apple gives no method to recover a lost backup password. Without that password you cannot restore a file from an encrypted backup.

  1. For protection of the backup from other persons, set Encrypt Backup to on.
    • An encrypted backup needs a password at each restore.
    • Your Mac can ask for the password when you connect the disk or when you start the Mac.
    <1m
  2. If Encrypt Backup is on, type a password for the backup disk.
    • Apple gives a password hint that helps you remember the password.
    1m
  3. Make a record of that password in a safe place.
    • The password for the backup disk is not the password for your Mac.
    1m
  4. Select Done.
    • Your Mac starts the first backup immediately.
    <1m

Make the first backup

Estimated 1 min (partly estimated)

NOTEThe first backup copies all the files. Later backups copy only the files that changed.
How long a local snapshot is kept on an APFS disk
Manufacturer or standard verified
Up to 24 hours, or until the disk needs the space

Source: Back up your files with Time Machine on Mac · tier 1 · accessed 2026-07-29

  1. Find the Time Machine icon in the menu bar.
    • If the icon is not in the menu bar, open System Settings.
    • Select Control Center in the sidebar.
    • Find Time Machine in that list.
    • Select Show in Menu Bar.
    <1m
  2. Select the Time Machine icon.
    <1m
  3. Read the progress of the backup at the top of the menu.
    • The menu shows the completed part of the backup, or the date of the last backup.
    <1m
  4. Let the first backup continue to the end.
    • The first backup copies all the files and takes the most time.
    • You can use your Mac at the same time.
    • To start a backup immediately, select Back Up Now.

Set the backup options

Estimated 2 min to 6 min

Automatic backup schedule
Manufacturer or standard verified
Hourly for the past 24 hours, daily for the past month, then weekly for every earlier month

Source: Back up your Mac with Time Machine · tier 1 · accessed 2026-07-29

  1. Select the Time Machine icon.
    • Select Open Time Machine Settings.
    <1m
  2. Select Options.
    <1m
  3. Select a value in the Backup Frequency menu.
    • This menu also has a manual setting for a backup only on your command.
    <1m
  4. If your Mac is a laptop, set Back up on battery power to on.
    • This setting shows only on a Mac laptop with an automatic schedule.
    <1m
  5. Select the add button below Exclude from Backups.
    • Then select a folder in the list that opens.
    • Time Machine does not copy an item in that list.
    • Your Mac adds the backup disk to that list automatically.
    1m
  6. Select Done.
    <1m

Restore one file from the backup

Estimated 3 min to 7 min

NOTEA backup that gave no file back is not a backup. Do this section one time, before you rely on the backup.
Oldest macOS that can restore a backup made on macOS 12 or later
Manufacturer or standard verified
macOS 11

Source: Back up your files with Time Machine on Mac · tier 1 · accessed 2026-07-29

  1. Open a Finder window for a folder with files in the backup.
    • The Documents folder is a satisfactory example.
    <1m
  2. Open Time Machine with Spotlight.
    • Time Machine is in the Other folder.
    • Your Mac can take some seconds to connect to the backup disk.
    <1m
  3. Use the arrows at the side of the window to go to an earlier backup.
    • The timeline at the right shows the selected backup in red.
    <1m
  4. Select one file in that backup.
    <1m
  5. Select Restore.
    • Your Mac puts the file back in its initial folder.
    • If the file comes back, the backup is good.
    <1m

Disconnect the backup disk

Estimated 1 min

NOTICE

EJECT THE BACKUP DISK BEFORE YOU DISCONNECT IT FROM YOUR MAC.
Apple gives an eject of the disk, or a shutdown of the Mac, before each disconnection.

  1. Eject the backup disk before you disconnect it from your Mac.
    • Apple gives a shutdown of the Mac as an alternative to the eject.
    <1m
  2. Connect the backup disk to your Mac again at regular intervals.
    • Time Machine continues its schedule after each new connection.
    • A backup disk in a drawer gives you no protection.
    <1m

Terminology

This page uses one term for each item and holds it throughout, as ASD-STE100 requires. Equipment sellers and other guides use the names below for the same parts.

Time Machine
Also called: mac backup, apple backup, time machine backup, macbook backup, the backup thing on a mac
backup disk
Also called: backup drive, external hard drive, external hard disk, time machine drive, backup hard drive, usb drive, portable drive
System Settings
Also called: system preferences, mac settings, settings app, preferences, control panel on a mac
APFS
Also called: apple file system, mac format, disk format, apfs encrypted
local snapshot
Also called: snapshot, time machine snapshot, local backup, backup without the drive plugged in
Encrypt Backup
Also called: encrypted backup, backup password, time machine password, password protect my backup, encrypt time machine
restore
Also called: recover, get my files back, undelete, roll back a file, recover a deleted file on mac

When to use a professional

Stop if your Mac cannot find the backup disk after the setup. Read the Apple topic about Time Machine problems in the sources. Then speak to Apple Support.

Stop if a backup fails or stops before the end more than one time. A repeated failure can come from the disk hardware. Speak to Apple Support or to the disk manufacturer. Give them the macOS name and the macOS version from the first section.

Stop if you cannot remember the password for an encrypted backup. Apple gives no method to recover that password. Make a new backup on a different disk. Then speak to Apple Support about the old disk.

Stop if the internal disk of your Mac has a fault. A restore of your files cannot repair a damaged macOS installation. Speak to Apple Support.

This page does not give the steps for a backup to a network. A shared Mac, a NAS device and an AirPort Time Capsule are each different. The instructions for a NAS device come from the NAS manufacturer.

Common questions

How big does my Time Machine drive need to be?

Apple's answer is at least twice the storage capacity of your Mac, and its own worked example is a 1TB Mac wanting a 2TB backup disk. That is a floor, not a target: Time Machine keeps old versions of files as well as current ones, so the more history you want the more room it needs. Apple also says the Mac will tell you when Time Machine needs more space, which is the honest version of this answer — you find out in use. We are not going to name a drive model, because that number depends on your Mac and on how much you keep, and a page that guesses it is guessing with your files.

Can I use the same drive for backups and for my other files?

Apple says to use the Time Machine backup disk only for Time Machine backups. There is a documented exception for advanced users: add a second APFS volume to the same physical drive and use one volume for Time Machine and the other for storage. Apple's caveat is that the Time Machine volume should still be twice the storage capacity of your Mac, and the two volumes share the drive's space. If you simply drop files onto the backup disk instead, Apple is explicit that Time Machine will not back those files up and the space left for backups shrinks.

Should I turn on Encrypt Backup?

It depends on what happens if the drive is lost or stolen, and only you know that. What matters more is the part people find out too late: Apple documents no way to recover a lost backup password, and you must supply it to restore anything from an encrypted backup. So the real question is not whether to encrypt, it is whether you have somewhere reliable to keep the password — a password manager, or paper somewhere safe. If you do not, an unencrypted backup you can actually restore from beats an encrypted one you cannot. Apple also notes you may be asked for the password when you connect the disk or restart the Mac, not only when restoring.

Does Time Machine back up everything, so I could rebuild my whole Mac from it?

Not by itself, and this is the most common misunderstanding about it. Apple states that Time Machine excludes system files and the apps installed as part of macOS. If the system is damaged, Apple's documented route is to reinstall macOS first and then use Migration Assistant to bring your information back from the Time Machine backup. So the backup does hold your files, your settings and your third-party apps, but it is not a bootable clone and it is not a one-click rebuild.

What are local snapshots, and do they mean I don't need a drive?

No. Time Machine also saves local snapshots on the same disk as your original files, which lets you recover an earlier version of a file even when the backup drive is not attached. Apple says those snapshots are created hourly, are only made on disks using APFS, and are kept for up to 24 hours or until the disk needs the space. That makes them useful for the file you broke this morning and useless for the disk that failed this afternoon, because they live on the disk that failed. Apple's own recommendation is still to back up to somewhere other than your internal disk.

Can I back up to a network drive or a NAS instead of plugging a drive in?

Apple supports it, and this page deliberately does not instruct it. Time Machine can back up to another Mac shared as a backup destination, or to a third-party NAS that supports Time Machine over SMB, and Apple's guidance is to prefer SMB where you get the choice. Two things are moving, though: Apple says backups to NAS devices over AFP are not recommended and will not be supported in macOS 27 or later, and that the shared-Mac route is only recommended when both machines are on macOS 11 or later. NAS setup instructions come from the NAS manufacturer, not from us and not from Apple.

How often does Time Machine actually back up?

By default, hourly backups for the past 24 hours, daily backups for the past month, and weekly backups for every month before that. When the disk fills, the oldest backups are deleted to make room, which is normal behaviour rather than a fault. You can change the interval in Time Machine settings under Options, using the Backup Frequency menu, and that menu includes a manual setting if you would rather back up only when you say so. On a Mac laptop there is a separate switch for backing up on battery power.

My Mac shows System Preferences, not System Settings. What now?

You are on macOS Monterey 12 or earlier, and the steps on this page will not match your screen. Apple renamed System Preferences to System Settings in macOS Ventura 13 and moved Time Machine under General, which is the layout this page follows. Time Machine itself works on the older releases; the route to it is just different, and Apple's support article has a separate section for the setup steps in your version of macOS. Read your version from the Apple menu, then About This Mac, before you follow anything.

Sources

Every specification on this page is traced to one of these sources. Tier 1 is a manufacturer document, a published standard, or a government safety authority. See Standards for the full tiering rule.

  1. Tier 1Back up your Mac with Time MachineApple Inc. · accessed 2026-07-29 · re-verification due 2027-01-25
  2. Tier 1Backup disks you can use with Time MachineApple Inc. · accessed 2026-07-29 · re-verification due 2027-01-25
  3. Tier 1Back up your files with Time Machine on MacApple Inc. — Mac User Guide for macOS Tahoe · accessed 2026-07-29 · re-verification due 2027-01-25
  4. Tier 1Choose a backup disk and set encryption options on MacApple Inc. — Mac User Guide for macOS Tahoe · accessed 2026-07-29 · re-verification due 2027-01-25
  5. Tier 1Types of disks you can use with Time Machine on MacApple Inc. — Mac User Guide for macOS Tahoe · accessed 2026-07-29 · re-verification due 2027-01-25
  6. Tier 1Exclude files from a Time Machine backup on MacApple Inc. — Mac User Guide for macOS Tahoe · accessed 2026-07-29 · re-verification due 2027-01-25
  7. Tier 1Restore items backed up with Time Machine on MacApple Inc. — Mac User Guide for macOS Tahoe · accessed 2026-07-29 · re-verification due 2027-01-25
  8. Tier 1Start, pause, or resume a Time Machine backup on MacApple Inc. — Mac User Guide for macOS Tahoe · accessed 2026-07-29 · re-verification due 2027-01-25
  9. Tier 1Time Machine settings on MacApple Inc. — Mac User Guide for macOS Tahoe · accessed 2026-07-29 · re-verification due 2027-01-25
  10. Tier 1About the Time Machine backup password on MacApple Inc. — Mac User Guide for macOS Tahoe · accessed 2026-07-29 · re-verification due 2027-01-25
  11. Tier 1Time Machine troubleshooting on MacApple Inc. — Mac User Guide for macOS Tahoe · accessed 2026-07-29 · re-verification due 2027-01-25

Revision history

Current version 1 · updated 2026-07-29 · next review due 2027-07-29

  1. v1 · 2026-07-29First draft. Built entirely from Apple's own documentation, opened by direct HTTPS fetch on 2026-07-29: the support article 'Back up your Mac with Time Machine' (Apple published date 6 July 2026), 'Backup disks you can use with Time Machine' (published 7 July 2026), and the Mac User Guide topics 'Back up your files with Time Machine on Mac', 'Choose a backup disk and set encryption options on Mac', 'Types of disks you can use with Time Machine on Mac', 'Exclude files from a Time Machine backup on Mac', 'Restore items backed up with Time Machine on Mac', 'Start, pause, or resume a Time Machine backup on Mac', 'Time Machine settings on Mac', 'About the Time Machine backup password on Mac' and 'Time Machine troubleshooting on Mac'. The guide identified itself as the Mac User Guide for macOS Tahoe on that date. Five Mac User Guide URLs in wide circulation return HTTP 200 while redirecting to the guide index, which means the status code looks healthy and the cited content is not served; those are recorded under rejected in data/sources-additions-set-up-macos-time-machine.json with their live replacements. The procedure was verified against Apple's documentation, not executed on a Mac, and this record says so rather than claiming a test result. Where Apple documents a network destination — a shared Mac, a NAS device, an AirPort Time Capsule — this page names it and does not instruct it, because the NAS half of those instructions belongs to the NAS manufacturer. The four verified specifications carry spec_key null: this record was drafted concurrently with others and the drafting session was not permitted to write data/specs.json, so the registry entries must be added when the record is merged. Each value traces to the Apple source named on it.

Corrections to this page are listed in the public corrections log. Reports that are credible and not yet verified are listed in the public errata register, and an open one renders above the step it concerns.

Comments and corrections

Found an error? A correction with a manufacturer source is applied and logged publicly. You can also write to corrections@fixchecklist.com.

Every step above carries its own report control, which tags the report with that step so a correction reaches the right place. For anything about the procedure as a whole — the order of the sections, a step that is missing, something that did not match your equipment — use this: report something about this whole procedure.

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