How Much Backup Space Do You Need?

Learn how to calculate how much space you need to backup your files. Do you need to backup just your important files or do you need to backup the whole drive? Get answers like to questions like this one.

It sounded like a good idea to back up your data, but all the size options are not making sense to you, how do you find out how much is enough?

Looking for used space:

Whether your on a Windows or a Mac there are ways to view how much space is taken up on your hard drive.


  • If your on a windows you can go to “My computer” then select the drive you have most of your data stored on. Right click on your drive (probably drive C:) and select properties. You will see a pie graph that shows your remaining drive space.
  • Also in windows if you want to measure the size of your folders you can right click on any folder and select ‘properties’ to see the folder size and space used for the folders.


  • On a Mac open your user’s ‘Macintosh HD’ that is usually in the top right corner of the screen. On the bottom of the finder window, it will display remaining disk space. You can also right click on ‘Macintosh HD’ and select ‘Get info’ to see more details.
  • Still in Mac you can find space used for files and folders too. Right click on a file or folder and select ‘get info’ to see the space used.
  • Mac file sync explained

It will be more accurate to measure the size of only documents that are created by you. Not software files or operating system files, but just the files that you create or manage yourself.

After you’ve gotten the sizes for several of your important documents you will start to see how much space you will need for online backup. You can choose between just uploading your crucial documents or you can upload all your files.

More information in these articles:

  • Family Online Backup Strategy
  • Business Online Backup Strategy