Wrong calculation of folder size by Windows

Anonymous
2018-06-28T18:16:18+00:00

Hello,

I noticed today that my Windows system does not properly calculate folder sizes.

I'm actually trying to make a backup of all my personal and work content. When I check the whole backup folder size under properties, It shows me around 10 Gb. But when I open this big folder and select a subfolder, It show me 30 Gb... This is kind of really annoying and I think it's a major issue Microsoft should fix ASAP.

I would like to say (because I didn't find anywhere else to post it) that in my opinion, Microsoft lacks ways of collecting feedback from his clients. There is nowhere we can manually report bugs and crashes.

In any ways, I think that showing correct folder sizes is a really basic task that an Operating System should be able to do. Such a bug is inacceptable for a leader like Microsoft, and I honestly consider going along with Apple if this issue does not get quickly fixed. My computer will soon need to be changed in anyways.

Meanwhile, if some of you guys have found ways to go around this major issue, feel free to share them :). Thank you!

Here is my technical information :

Intel Core i7-3720QM 2.60 GHz

64 bits

Windows 10 family version 1803

Installed on 2018-06-20

O.S. version 17134.112

Many thanks is advance,

Antoine

Windows for home | Windows 10 | Files, folders, and storage

Locked Question. This question was migrated from the Microsoft Support Community. You can vote on whether it's helpful, but you can't add comments or replies or follow the question.

0 comments
Answer accepted by question author
DaveM121 931.8K Reputation points Independent Advisor
2018-06-28T18:35:14+00:00

Hi Antoine_795,

It is widely reported that version 1803 of Windows 10 has introduced a bug into Explorer.exe

It is because it cannot read the metadata of files correctly, it mixes up the size and dimensions for example

Therefore it cannot calculate the size of a folder, especially if it has sub-folders, it also cannot calculate the spare space on a hard drive . . .

In the meantime, while we are waiting for Microsoft to fix this bug:

Click the link below to download a small free utility called Treesize - it is a great utility . . .

Using that tool, you will instantly see the size of all folders (always missing form File Explorer) and where space is being used on your hard drive . . .

https://www.jam-software.com/treesize_free/

________________________________________________________

Standard Disclaimer: This is a non-Microsoft website. The page appears to be providing accurate, safe information. Watch out for ads on the site that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the site before you decide to download and install it.

Was this answer helpful?

40+ people found this answer helpful.
0 comments

105 additional answers

Sort by: Most helpful
Most helpful Newest Oldest
  1. Anonymous
    2019-07-09T15:35:39+00:00

    GeoffHarders is correct.  I just discovered this problem when I was trying to verify that a backup folder had completed and all the files from my C to my E had copied.  The original folder said it had 25Gig.  The backed up folder said it had 10Gig.  The same backup folder on D had 475 Gig!  I kept trying to search through the files and folders to see if I'd accidentally made recursive backups.  Finally in desperation I googled it and came across this folder, which indicated that the numbers I was seeing was pure hogwash.  I downloaded the Treesize and, indeed, the folder size in D and C were exactly the same (indicating the folder had completely backed up to D), and it also showed that the  E folder had not yet completed - which was what I needed to know.

    Thank you all for your help with this.  And let's hope that Microsoft actually fixes this bug someday.

    Was this answer helpful?

    0 comments
  2. Anonymous
    2019-07-04T19:51:05+00:00

    Had the issue of not only folder size but the issue of real mismatch of files within a folder verses folder size.

    This happened when I unknowingly copied an NTFS formatted drive to an exFAT drive. The problem of mismatch was huge - by almost 50%. However, did not realize the formatting mismatch until after reading some of the posts on this forum and doing some investigation.

    Since these drives are good size local storage (4 TB+) and since in a former career I had issues with file name lengths on MSFT equipment, took the info and realized that the difference in file table spaces and long paths within the disk formats could be entering the issue. With such large drives, I took the time (16 hours+) to reformat the receiving drive (low level) from exFAT to NTFS.

    I then copied again from the backup NTFS to the newly reformatted archive NTFS - no issue. Match on everything but size on disk which is to be expected due to random loading of the backup drive verses the serial loading done during a copy.

    I am on Win10Pro 1903 (OS - 18362,207) on an Intel Xeon.

    My read is that the file tables of the older formats (exFAT) cannot handle path names that NTFS can and that causes the bad reporting.

    My suggestion is to look at the older drives that you are having the issues with and try to bring everything up to NTFS. After all, 100% backwards compatibility is not always possible from my view even though it would be nice.

    Was this answer helpful?

    0 comments
  3. Anonymous
    2019-07-04T01:54:51+00:00

    Agreed - I have a 4.6 gig file that I want to copy onto a brand-new 32 gig Sandisk flash drive, and Windows Explorer tell me it's too big to fit on the flash drive - useless!!!!

    use a copy tool like ultracopier

    Was this answer helpful?

    0 comments
  4. Anonymous
    2019-06-03T10:42:38+00:00

    FINALLY MY WINDOWS10 PRO UPDATE TO VERSION 1903, AND THIS PROBLEM ALREADY FIXED!!!

    FOLDER SIZE NOW CALCULATE GOOD

    Was this answer helpful?

    0 comments