Both macOS and Windows allow users to format their hard drives using built-in utilities. Even though most people associate formatting with system installation, there are many other reasons why you might want to format your hard drive.

It could be because the storage device is experiencing an issue or maybe you purchased a new external storage device and are trying to get it to work with your Mac or Windows computer.

In this article, we will take a look at the various ways you can format a storage device on both Mac and Windows.

First, let’s talk about the common situations for when you might need to format a storage device in the first place.

hard drive format mac

Common Situations When You Need to Format a Hard Drive

There can be many reasons why you may need to format a storage device.

  • 💵 Purchased a new external hard drive and you’re ready to set it up and use it.
  • 🎁 You received a storage device from someone and want to erase the contents on it so that you can start using it.
  • 💽 You have a storage device that you want to erase to free up the space on it for new data. This can be a common scenario for when you’ve taken pictures or files off of a storage device and put them onto your computer and now you don’t have a need for them on the external device anymore.
  • 👩🏻‍🔧 The storage device is experiencing issues and isn’t working correctly. A format can usually fix this as the device might have corrupt data on it.

Regardless of why you want to format your hard drive, there are some considerations to be made before you begin. First and foremost, you need to decide which file system to use. Let’s take a look at and talk about which file system you may want to choose.

How to Choose a File Format

In short, if you’re on Mac use APFS (Apple File System) and if you’re on Windows, use NTFS. Both of these are the newest, fastest, and securiest file systems available on both operating systems. Let’s take a deeper look into file systems for those that are curious and want to know more.

macOS uses the Apple File System (APFS), while Windows uses the NTFS file system. Let’s talk a little bit about each of these file systems and the others that you might consider and the benefits of each.

System Overview
NTFS Default and modern file system used by Windows and this is the preferred file system that should be used.
APFS Apple File System is what is what your Mac will use by default. It is fast and efficient and this is the file system that you should use unless you have other specific needs.
Mac OS Journaled Uses the Mac format (Journaled HFS Plus) to protect the integrity of the hierarchical file system. Choose this option if you don’t need an encrypted or case-sensitive format.
Mac OS Extended (Journaled, Encrypted) Uses the Mac format, requires a password, and encrypts the partition.
exFAT This file format is best for external devices such as USB thumb drives and external hard drives due to how it works with USB connections. You can also use this data format on both Mac and Windows together.
HFS+ File format used on Mac before APFS. There isn’t much of a reason to use this file format anymore.
FAT32 Older file system and isn’t as fast or efficient as NTFS. A drawback of this one is that it won’t support larger file formats. It is best to use NTFS or exFAT instead.

Now that we’ve taken a look at file formats, let’s move into actually formatting the external hard drive.

How to Format an External Hard Drive on Mac

macOS users have at their disposal a handy tool called Disk Utility. With it, it’s possible to easily format a storage device with just a few clicks. You can launch it from the Applications folder or use Spotlight. The main window of the utility contains a list of storage devices, storage device details, and formatting options.

Let’s take a look at how to format a storage device on a Mac.

  1. Connect the storage device that you want to format to your Mac.
  2. Go to Applications and Utilities and launch Disk Utility. The application will appear as shown below with a list of available storage devices on the left and various disk management options on the right. At the bottom of the main window are storage device details, including disk description, connection type, USB serial number, total capacity, write status, S.M.A.R.T. status, and partition map scheme.disk utility mac
  3. Select your storage device from the list on the left and click on the Erase tab. Before you can click on the Erase button located in the Erase tab, you must select which file system you would like to use and give it a name. If you’re not sure which option you should choose, check out our previous section where we went into detail about what data format you should use.How to Format USB Flash Drive on Mac
  4. Give your external hard drive a name and then choose what data format you would like to format to. Click on the Erase button to start the formatting process. Depending on the size and speed of your storage device, it may take a minute or two. Once the formatting process is finished, you should be able to transfer files to the newly formatted flash drive.

That’s it! Formatting on macOS is an easy and a straight forward process. Now, let’s take a look at how to do it on Windows.

How to Convert a Mac Formatted Hard Drive to Work on Windows

When you use an external hard drive with a Mac, it most likely is going to be using APFS which is Apple’s file system. This file system won’t be recognizable by a Windows machine so the hard drive will have to be formatted before it can be used on a Windows machine.

Before formatting to Windows, you might want to back up your data if you have anything important on the external hard drive. You can use Disk Drill’s Byte-to-byte backup feature which we talk about later in the article if you do have data that you want to save. The backup feature is free and is super easy to use.

If you’re unsure as to what data format to format your device to, take a look at the section above as we dive into which format you may want to use based on the use case of the external hard drive.

Formatting an external hard drive on Windows can be accomplished in just a few steps.

  1. To format a hard drive for Windows, open the File Explorer and click on This PC. If the hard drive you want to format is connected to your PC, it should be there.
  2. Right-click on it and select the Format option from the context menu. Keep in mind that you can only format storage devices that are currently not in use. Windows will present you with a formatting window where you can specify various formatting parameters.format parameters
  3. After you confirm your selection, it should take just a few moments for the formatting process to finish.external drive successful reading

Now that we know about data formats and how to format an external hard drive on both Mac and Windows, let’s take a look at what we can do if we lose data on one of these external hard drives.

How to Recover Data From a Formatted Hard Drive on Mac

If you’ve ever lost data after a format or if your external hard drive isn’t working correctly and you want to try to recover a file before formatting it, then third-party data recovery software will work great for you!

Disk Drill allows us to recover files even after they’ve been deleted from our computer. I love using Disk Drill because it’s fast, modern, and it seems to be able to always find the files that other third-party data recovery can’t find.

In the example below, I will be walking through data recovery on a Mac but the steps are pretty much the same for a Windows computer as well.

Disk Drill
Data recovery for free
Your Companion for Deleted Files Recovery
  1. Download and install Disk Drill onto your Mac.
  2. Launch Disk Drill and scan the storage device that you would like to recover the lost files storage device
  3. Wait for the scan process to complete. This can take some time depending on how much data you have stored on the external device.scan in progress
  4. Once the scan process has been completed, you can review what Disk Drill was able to find.
  5. Select the files that you would like Disk Drill to recover and then click on the blue Recover button.preview feature in disk drill

You’ve now successfully recovered deleted files from your Mac. If you weren’t able to recover all of the files or if the process wouldn’t work at all, this could be because either the device was formatted which means there is a very slim chance that Disk Drill could find them or that it could be damaged.

Disk Drill can’t always get the files, but it’s always worth trying as it’s your best bet at getting them back after they’ve been deleted if you don’t have a backup in place.

What to Do If We’re Unable to Recover Our Data

Sometimes no matter what we do we can’t recover data from our storage device. If this is the case, then it might be best to reach out to a third-party data recovery center as they can attempt to recover the data.

CleverFiles offers a data recovery center that you can reach out to and send them external hard drive where they will examine it and see if any data can be recovered.

While this can become expensive, if the data on the device is very important to you and there is no price on it, then this option works well and is worth considering.

Bonus tip: Backup Your Files Before Reformatting

Before you reformat your hard drive, you might want to back up and save your data. This can be done by using Disk Drill’s Byte-to-byte backup process.

  1. Download and install Disk Drill.
    Disk Drill
    Data recovery for free
    Your Companion for Deleted Files Recovery
  2. Launch the app and connect an external hard drive or any other storage device that you want to back up to.
  3. Navigate to the Byte-to-byte backup section of Disk Drill.byte to byte backup disk drill
  4. Now, select the storage device that you want to back up to.byte to byte backup disk drill
  5. Choose the name of the backup and where you want to save the backup to. I just let Disk Drill choose the default name for the backup but you can change it to something custom if you would like to.
  6. Wait for the backup to complete.


Formatting an external hard drive can seem like a daunting task at first, but knowing what data type you should format to and how to go about formatting, makes the process all that much easier.

In addition, being able to back up the data on a computer ensures that if you want to save your data, you now know how to keep a copy of it.


Joel Lockard

Joel Lockard has had a love for technology his whole life. He works as an Airline Pilot and when not flying spends his time tinkering with technology especially Apple-related tech and Mac apps. He is always looking to mak...

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Approved by
Brett Johnson

This article has been approved by Brett Johnson, Data Recovery Engineer at ACE Data Recovery. Brett has a Bachelor's Degree in Computer Systems and Network, 12 years of experience.