How to Backup Your Apple Mac

Authored by: Support.com Tech Pro Team

1. Introduction: macOS: Backup Mac

Making sure you have a recent backup of your computer is extremely important. Apple has made this fast and easy, thanks to Time Machine for your Mac.

This guide will walk you through setting up Time Machine on your Mac.

2. Backups: Media Check

In order to perform a backup of your hard drive, you will need an external disk with enough space, plus a little extra, to store everything on your Mac currently.

To check how much storage space you'll need:

Select Apple menu > About This Mac.

Apple menu with About This Mac highlighted.

Select Storage at the top.

About This Mac dialog with Storage highlighted.

Here you'll see how much disk space is in use, and how much is available in total.

Storage dialog with space use highlighted.

In this example, we'd need a disk with a minimum size of 40 GB.
It is recommended to get a disk at least twice as large, about 80 GB in this example, so Time Machine can make 'snapshot' backups, so you can roll-back to previous versions as needed.

3. macOS: Connect External Hard Drive

Physically connect the USB cable that came with your external hard drive to the drive itself.

Example of an external hard drive and its supplied USB cable.

Connect the other end of the USB cable to your Mac computer.

USB cable being connected to an available USB port on a Mac.

An icon will pop up on the desktop of your Mac computer that will represent the hard drive that was just connected to the machine. Depending on what kind of drive you connected, this icon's appearance and label will vary.

macOS desktop screen displaying a successfully connected USB external hard drive.

To access the contents of this drive, simply double-click the icon. A Finder window will open to display it's contents.

4. macOS: Setup Time Machine

Select Apple menu > System Preferences.

Apple menu with System Preferences highlighted.

Select Time Machine.

System Preferences with Time Machine highlighted.

Select Select Backup Disk...

Time Machine with Select Backup Disk highlighted.

Select the disk you saw appear before, then select Use Disk.

Time Machine disk selection dialog with disk and Use Disk button highlighted.

Most new USB disks will come setup in a way not compatible with Time Machine. Time Machine will offer to erase the disk to work properly with Time Machine. If this prompt opens, select Erase.

Time Machine prompt to erase disk with Erase highlighted.

Time Machine will begin backing up your Mac immediately. If you'd like to monitor the process, place a check next to Show Time Machine in menu bar.

Time Machine with Show Time Machine in menu bar highlighted.

5. Backups: Get External Hard Drive

We will need an external disk to store the backup on.

Return to this guide when you have purchased an external hard drive.