Format External Hard Drive Title Image 2

External hard drives are great for Mac users. But you might have to format one before you can use it on your Mac.

There’s nothing worse than spending your money. And then realizing your drive is not compatible with your Mac.

The good news is that formatting an external hard drive for a Mac is quick and easy. It only takes a few minutes to do the job right.

You don’t need any special software or expensive tools.

Just follow these simple steps below, and you’ll be ready to start transferring files in no time!

Read on for a hand held walk through.

Format External Hard Drive For Mac

When you format an external hard drive for your Mac to use, you use Disk Utility.

This software program is a standard part of your Mac’s operating system. So there’s no software for you to buy.

A Side Note For You:

Formatting. Or reformatting your external hard for your Mac means you’ll lose any files on the drive.

For instance. If the drive you want to format has files on it from a Windows PC. Or you know that your brand new external hard drive comes with Windows PC software on it. And you want to use that software.

Copy those files off first.

But, if you’d prefer not to reformat your drive. Then read my article “External Hard Drive Compatible with Mac & PC without Reformatting” to find out how to do that.

Ready for your walk through? Let’s format the drive.

1. Start Up Your Mac And Log In.

Charge your MacBook Pro or MacBook Air or connected it power.  Particularly if your external hard drive is one powered by its USB cable.

The last thing you want is your Mac running out of power part way through formatting.

2. Plug In Your External Hard Drive.

Your drive will have a USB type A USB cable end.

USB A Cable End
USB Type A Cable End

Or a USB C connector for you to plug into your Mac.

USB C Cable End
USB C Cable End

New Macs only have USB C ports them.

And if you’ve a new Mac and a drive with a USB type A cable end. Then you’ll need an adaptor cable to plug in.

You can find out more about this in an article on the site “Connect an External Hard Drive to Mac, 12 things You Need to Know“. You can follow this link to take a look.

Your drive connected up?

You should now see your drive icon on your desktop.

It’ll look something like this.

New Drive Icon On Desktop
New Drive Icon On Desktop

No drive icon?

Try this.

Open up a Finder Window and click on finder preferences.

Finder Preferences
Finder Preferences

On the General Tab, check that the ‘External Drive’ box is checked.

Finder Preferences Show External Disks
Finder Preferences Show External Disks

This setting tells your Mac to show your drive icon on your desktop.

3. Now, Open Up Disk Utility.

You can start up Disk Utility from a Finder Window.

Click on your Application’s Folder. Then click on Utilities inside your Application’s folder

Finder Application Folder Utilities
Finder Application Folder Utilities

Inside the Utilities folder you’ll find the software.

Finder Disk Utility
Finder Disk Utility

Click to start the software up.

4. Inside Disk Utility.

Look to the left hand side of your pop up window.

On that side of the screen, you’ll see a list. Your Mac’s internal drive is at the top. And you’ll see your external drive underneath.

Right under the ‘External” heading is where you’ll find your drive.

Format Internal External drive list
Format Internal External drive list

Click on your new external hard drive under the external heading.

The red arrow in the picture above shows you where.

Take care to click on your drive at the right level.

Where the red arrow points.

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.

And later if you want to partition your drive you’ll have issues.

Can’t see the drive levels? Or there is only one level?

Click on the arrow to the left of your drive to show you the levels.

Did that work?


Look to the top of your Mac’s screen. Look for the ‘View’ option. Click and pick to ‘Show All Devices’.

Disk Utility Show All Devices
Disk Utility Show All Devices

Now you’ll see all the levels. And can pick your drive at the top level.

Picked your hard drive at the top level?

Good. Now you can go on.

5. Click Erase At The Top Of The Pop Up Window.

You’ll see a few options across the top of the pop up window.

Pick the erase option.

Select Erase
Select Erase

Don’t worry. You’re not erasing anything right now. You’ll need to set up a few things for your hard drive first.

Click Erase at the top of the window.

In the next window you type in the settings for the formatting of your drive.

Format Format Pop Up Window
Format Pop Up Window

6. Your Settings For The Format Of Your External Hard Drive.

First, give your drive a name. 

A quick tip.

You’ll find it easier later to pick name that makes it easy to find your drive on your Mac’s desktop. Pick a name that gives you a clue about what you’re using your hard drive for.

Underneath the name you set your drive’s format. This is the format you want for your external hard drive on your Mac.

You can pick APFS (Apple File System).

Or Mac OS Extended (Journaled) file system.

Or if you want a drive you can use with Mac and Windows pick ExFAT.

Things To Note:

Mac OS Extended (Journaled) is the format that’s the most compatible with newer and older Macs. APFS is best for SSD drives. But you can format your hard drive as APFS if you want.

Pick ExFAT if you want your drive read and writeable by both Mac and Windows.

All the above formats allow you to copy and paste from your Mac to your drive.

Drag and drop your files to your external hard drive.

But only APFS or Mac OS extended (Journaled) can you use for your Mac’s Time Machine backup.

Pick GUID Partition Map for the scheme.

This is important too.

Your Mac needs the GUID Partition Map scheme. Or you’ll have all sorts of odd problems using your drive later on your Mac.

Can’t see APFS (Apple File System) as an option?

Formatting an NTFS formatted drive?

This sometimes happens.

Pick Mac OS Extended (Journaled) the first time you format. Then format again.

APFS will come up as an option the second time round.

But still pick GUID Partition Map for your Mac.

The red arrows in the picture show you where you can find the format and scheme list of options.

7. Click On Erase.

Now you select the Erase button.

Your Mac will take a few minutes to format a hard drive.  And once done your external drive is ready for you to use.

You can then dismiss the window.

8. You’ve Formatted Your Drive On Your Mac.


When formatted you can use your drive just as you would a USB stick. But of course your external hard drive is way bigger.

Your drive will then show up on your Mac’s desktop.

You’ll see it with the name you’ve given it. And it’s all ready for you to use.

And when you’re ready to pack your drive away be sure to Eject your drive first.

Right Click to Eject
Right Click to Eject

Format External Hard Drive For Mac Frequently Asked Questions

1. Why Format An External Hard Drive For Mac?

Because a lot of hard drives out there on the market are NTFS formatted.

Your Mac can read an NTFS drive.

But you won’t be able to copy any files onto an NTFS drive. Or change any files on an NTFS drive. Unless you either use special software. Or format the drive for your Mac.

The great thing about your Mac is that it’ll use any drive out there. As long as it’s in the right format. And you can change that in 5 minutes or less.

2. Format An External Hard Drive For Your Files

When you want to copy and paste your files. Or drag and drop your files to your drive.

Then pick APFS (Apple File System). Or Mac OS Extended (Journaled) (HFS+).

Or ExFAT if you plan to use your drive to share between Windows and Mac.

One thing to bear in mind.

If you’ve older Macs running the operating system High Sierra or earlier. Then pick Mac OS Extended. As that’s the compatible format for older Macs.

3. Format For Your Mac’s Time Machine Backup

Want to use your shiny new drive for Time Machine?

You’ll need to format it to APFS or Mac OS Extended File system.

But understand that your Time Machine backup on your APFS formatted drive. Can only be read by a Mac running Big Sur.

The option to do a Time Machine backup to an APFS formatted drive. Came in with the Big Sur operating system version.

Older Macs running Catalina. Or older operating systems can’t read a Time Machine backup on APFS.  And for now, Apple has no plans to add that option to those older operating systems.

So, if you’re sharing your Time Machine backup drive with older Mac’s. Then pick the Mac OS Extended format for your drive.

And if you want to know how to hook up your new hard drive to Time Machine. Read my article on the site here. How To Backup To External Hard Drive.

In a few more steps you’ll have that all set up too.

4. I Click On Erase And Get An Error

Erase Process Failed
Erase Process Failed

Check you have picked your drive at the top level in Disk Utility. And before going to your formatting options screen.

Format Internal External drive list
Format Internal External drive list

If you have. Check your drive.

Click on ‘First Aid’ at the top of your pop up window. Run a check on your external hard drive to make sure all is well with it.

5. What If I Want To Partition A New Hard Drive For Windows And Mac?

When you have a new hard drive that’s a decent size. And you want to format and partition your drive.

You’ll find an article that shows you how to do it right here on the site. Just follow the link text. Partition Hard Drive For Mac and Windows.

In Closing

And now you have your external hard drive formatted for your Mac.

You’ve a lot of choices in choosing an external hard drive for your Mac.

You can get one that is pre-formatted to work with your Mac’s operating system. Or you can format any hard drive yourself.

The choice is yours and you’ve now got all the information you need!

Why not look at some related posts on our site as well?

Related Articles

(Which To Pick?) Best Format For Mac External Hard Drive

(Which Is The Best?) Format For Mac Time Machine Backup

External drive for Mac and PC with Files Interchangeable

What’s the Best External Hard Drive for Mac. Find a Great One Fast


  1. Hey folks: thanks for the helpful suggestions about how to activate my new external hard drive from Seagate. Much appreciated.

    1. Hi Bill, You’re welcome. I’m glad that you found the post helpful. Your comment is much appreciated.

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