Hi everyone,

When I purchased my hard drive, its size was 1TB. Iformatted it a few times and I don't know why and how it has lost 70GB. Is there a way that I can get it back up to its original size?

if yes, Will I be able to do the remove operation on it while it is plugged in?

4 Years
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Last Post by technoknol
  1. no, formatting creates, in simple terms, an index to store the location of all other files that file box occupies some space

  2. drive makers TB are not TB. drive makers use decimal 1000 everyone else uses binary 1024 (2x2x2x2x2x2x2x2x2x2) as the basis for kilo mega giga tera
    drive makers write 1 tb = 1 000 000 000 000 bytes
    terabytes by chkdsk are = 1 099 511 628 xxx bytes (calculator only shows 10 significant digits) = 91%, formatted drives lose 9% without losing anything, because chkdsk reports binary size.


Does that mean every time I format my hard disk, it will lose 9%, according to your figure, of its size?


Almostbob is right.
To answer your second question, no. You wont lose an additional 9% every format. But no matter what you do, every time you format, there will be the same 9% missing. Formatting a disk gets it ready for information. Without formatting it (NTFS, FAT32, EXT4, etc) the computer doesn't know how to write and store data onto the drive therefor renderring it useless. Formatting the drive, no matter which format you use, clears the data that was existing on there, and prepares it to write, store, and access data in a partifular way.


Thanks for the answer. I thought it is too ridiculous to lose 50 or 70 GB of the hard drive size.


Right guys. Almostbob will not lose 9% of actual space everytime he format the HD. As we all know, if we get a flash drive of 1GB, it actually carries 972 MB. That is the same case. I hope rotten69 has no doubt further.


Actually, you do not loose any space at all. The problem is not that space is missing during the format, its actually a marketting problem as almostbob pointing out in #1 of his post.

Storage vendors do not actually label their products correctly. In the example above, if you buy a 1 TB drive, you are getting 1,000,000,000,000 bytes.

All you need to do is the math to figure out what this really translates to.

  • 1024 Bytes = 1 KB
  • 1024 KB = 1 MB
  • 1024 MB = 1 GB
  • 1024 GB = 1 TB

Therefore you can take the number above and start dividing..

1,000,000,000,000 Bytes (/1024) = 976,562,500 KB
976,562,500 KB = 953,674 MB
953,674 MB = 931 GB
931 GB = .9 TB

So, because of the way they market the numbers, you are getting 70 GB less than what you are expecting.

Edited by JorgeM


Hard Disks are built based on Mebibytes/teribytes which is almost analogous to Megabytes/Terabytes. The calculation is based on the above post.


It can be happen by two reason
1 Your space will be unallocated. Check it by Right Click Computer > Manage > Disk Management. There you will find a partition with black colour which is unallocated.

2 It can happen if you have formatted it with NTFS file system than it will hog some space as system resvered space.

Mark it as solved if it solves your issue.

Edited by technoknol

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