You’ve got your external hard drive in hand. And you’re just not sure how to format your external drive right for a Time Machine backup.
Don’t worry. I’ll show you how I get my formatting done.
Read on for the answer to your question ‘How do I format a Mac external hard drive for Time Machine?’
By the way. These steps work if you’re formatting an external SSD for a Time Machine backup.
Format External Hard Drive For Mac Time Machine Overview
You’ll have your external hard drive formatted for Time Machine as part of your set up with Time Machine. This is true as of Mac OS Ventura.
For earlier Mac operating systems check out that section in the article below.
1. Connect Your External Hard Drive.
2. Open System Settings. Click General. Then Time Machine.
3. Click Button ‘Add Backup Disk’.
4. Pick Your External Hard Drive. Then Click ‘Setup Disk
Time machine then formats your hard drive ready for Time Machine. Then sets your external hard drive as your time machine backup drive.
Read on for the full walk through of the steps.
How To Format External Hard Drive For Mac Time Machine
From Mac OS Ventura, to format your external hard drive for an Apple Time Machine backup, you simply set up your external storage space as a Mac backup drive.
There is no need to separately format first. Apple has made things easier for you as a Mac user.
This is how I do it.
Pause For A Moment:
Formatting. Or reformatting an external hard disk means. Any files on your drive will be erased.
If the drive you plan to use for your Time Machine backup already has files on it.
Copy those files off first.
Because after formatting those files will be gone. And if they are important files, you’ll be seeking the services of a data recovery company to recover data.
Ready? Let’s go.
1. Connect Your External Hard Drive.
Log in to your MacBook Pro or Air. Then plug in your external hard drive into your Mac’s USB port.
In a few moments your drive icon should show up on your desktop.
It’ll look something like this.

When no drive icon shows up on your Mac’s desktop. Then you’ll need to check your Finder Settings.

Click on the General tab. Then be sure that the ‘External Disks’ box is checked.

This setting tells your Mac to show your drive icon on your desktop.
2. Open System Settings. Click General. Then Time Machine.
Open System Settings. You can find your System Settings from your Apple Menu. Top left on your Mac’s desktop.

Scroll down to General. Click there.
Then scroll down to Time Machine and click that option.

3. Click Button ‘Add Backup Disk’.

Click the on the Button ‘Add Backup Disk’.
4. Pick Your External Hard Drive. Then Click ‘Setup Disk.
Then click your hard drive storage space on the popup window.
Note: Your Mac will format your whole hard drive as a Time Machine drive. If you have any files you want on your drive. Cancel and copy that data off somewhere safe first.
Next click Setup Disk

Your Mac will then format your external hard drive as a Time Machine backup drive. And set your drive up as APFS (Apple File System) for Time Machine.
Show Time Machine Icon In The Menu Bar
It’s a good idea to tell your Mac to show the Time Machine icon in your Mac’s menu bar. You’ll find this useful for checking on your backups. And manually kicking off a backup later.
Still in System Settings. Click on Control Centre. Then scroll down to Time Machine. Then click the option ‘Show In Menu Bar’.

Formatting External Hard Drive For Time Machine (Monterey And Earlier)
In Mac OS Monterey and earlier Mac operating systems you use disk management software on your Mac. So, there’s no software for you to buy. It’s a standard part of your Mac’s operating system.
The software is called Disk Utility.
1. Connect Your External Hard Drive.
Log in and connect your external hard drive into your Mac’s USB port. In a few moments your hard drive’s icon appears on your Mac’s desktop.

No drive icon?
Try this.
Open up a Finder window and click on Finder Preferences.

On the General tab, check that the ‘External Disks’ box is checked.

This setting tells your Mac to show your drive icon on your desktop.
2. Open Up Disk Utility.
Start up Disk Utility from a Finder Window.
Click on your Applications folder. Then click on Utilities inside your Applications folder.

Inside the Utilities folder you’ll find the Disk Utility software.

Double click to start Disk Utility.
3. Click On Your Drive. Click Erase.
Look to the left hand side of your Disk Utility pop up window.
There, you’ll see a list of all the drives attached to your Mac computer.
Your internal drive is at the top under the heading ‘Internal’.
And the drive you plan to use for Time Machine under the ‘External” heading.

Click on your external hard drive. Click right where it first appears under the external heading.
The red arrow in the picture above shows you where.
But you’ll need to be sure you click on your drive at the right level.
Where the red arrow points.
You should see several levels for your drive.
If you can’t see the drive levels. Or you can only see one level. You’ll need to set your Mac to open up the levels.
Click on the arrow to the left of your drive. Did that open things up?
No?
At the top of your Mac’s screen. Pick the Disk Utility ‘View’ option. And from that menu pick the option to ‘Show All Devices’.

Now, try the arrow to the left of your drive’s name again. And open up the levels. Then click your drive at the top level.

Picking your drive at a lower level will give you all sorts of problems. Including your drive not formatting. And errors when you format the drive.
Now you’ve clicked your drive at the top level look across the top of the Disk Utility pop up window.
From there click on Erase.

Don’t worry. You’re not erasing anything yet. There are a few things to set up for your formatting first.
In the next window you type in the settings for the formatting of your drive.

4. Type in a Name For Your Drive.
You’ll need to type in a name. Pick something that makes it easy for you to know this is your Apple Time Machine drive.
5. Pick APFS Or Mac OS Extended File System.
In the Format field you can pick APFS (Apple File System). Or Mac OS Extended (Journaled) file system.
And which you pick depends on the current format of your drive. The age of your Mac and the operating system your Mac is running.
When your drive is an NTFS formatted drive. You’ll need to pick Mac OS Extended (Journaled) the first time you format.
Because your Mac needs to change the Windows PC format of a NTFS drive to a Mac file format first.
Even if you want your backup disk in APFS format. You’ll have to pick Mac OS Extended format first. Then format a second time and you’ll see the APFS format comes up as an option to pick.
This is also true if your external disk drive is currently in an ExFAT format.
When your Mac is running a Mac OS X version that’s Catalina or earlier. You’ll have to pick Mac OS Extended format. Because those older Mac OS X versions can’t use an APFS formatted external drive for a Time Machine backup.
APFS support for Time Machine was only available since Mac OS Big Sur.
6. Set Scheme As GUID Partition Map.
Pick GUID Partition Map for the scheme.
This is important. No matter which Mac file format you pick.
Your Mac needs the GUID Partition Map scheme. Or you’ll have all sorts of odd problems using your drive later on your Mac.
Don’t pick Apple Partition Map. It’s only used for much older PowerPC based Mac computers.
The red arrows in the picture show you where you can find the format and scheme list of options.
7. Click On Erase.
You’re ready now to format. Happy there are no files you want on your drive? Then click the Erase button.
Your Mac will take a few moments to format your hard drive. You’ll get a message telling you your Time Machine backup drive is formatted.
Exit your Disk Utility window.
Your backup drive’s icon will show up on your Mac’s desktop.
You’ll see it with the name you’ve given your backup disk underneath. And it’s all ready for you to connect your drive in System Preferences to Time Machine.
Head over to this article on the site to learn how. Time Machine Backup External Drive.
And when you’re ready to pack your drive away be sure to Eject your drive first.

In Closing
And now you have your external hard drive formatted as storage for your Time Machine files.
Use on your M1 Mac, MacBook Pro or Air.
And it only took you a few minutes to do today.
While you’re here do check out our other recommended articles on external hard drives.
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