You’ve got your external hard drive in hand and you’re planning to use it for your Mac’s Time Machine backup.
But, you’re just not sure how to format your external drive right for Time Machine.
Don’t worry. You don’t need any special software or tools.
And in a few minutes you’ll have got it done.
Read on for the answer to your question ‘How do I format a Mac external hard drive for Time Machine?’
These steps also work if you’re formatting an external SSD for a Time Machine backup.
Format External Hard Drive For Mac Time Machine Overview
1. Connect your external hard drive.
2. Open Disk Utility. Applications > Utilities folder > Disk Utility.
3. Click on your drive. Click Erase.
4. Type in a Name For Your Drive.
5. Pick APFS or Mac OS Extended File System.
6. Set scheme as GUID Partition Map. Click Erase.
Read on for the full walk through of the steps.
How To Format External Hard Drive For Mac Time Machine
To format your external hard drive for an Apple Time Machine backup. You’ll 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.
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.
Charge your MacBook Pro, Air or Mac Mini. Or connected up to power.
The last thing you want is your Mac running out of power part way through your formatting.
Log in to your Mac. Then plug in your external hard drive.
Use the right USB cable end or adaptor for your generation of Mac. And for your external drive.
In a few moments your drive icon should show up on your desktop.
It’ll look something like this.
No drive icon?
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?
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 Uility 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 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. 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. And also with the MacOS Monterey. So, don’t use APFS for OS X versions older than that.
Another thing. APFS is best for SSD drives. Because it was designed and optimized to take advantage of the speed of APFS drives. But you can run APFS on external hard drives too.
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. And ready for you to attach to Time Machine.
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 use your Mac’s System Settings. Or in Mac OS Monterey or older you’d use System Preferences and connect your backup drive 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.
And now you have your external hard drive formatted as a Time Machine drive.
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 related posts on external hard drives.
About Simon Irons
As an admin I spend my day helping folks with their Mac issues. From the guy at work, through to unofficial 911 support for family and friends. I swear they have me on speed dial.
For fun I like testing out and playing with new stuff. I think Apple make the best products on the planet.
In my spare time I like to fish and play around with boats.