OneDrive Shows More Usage Than Expected

Who This Affects and What to Know

This behavior affects anyone using OneDrive or SharePoint file sync on a Windows 11 computer. You may notice that files or folders appear to consume far more storage than your physical disk even holds — in some cases up to three times the actual disk size. There is no error and no fix required; this is simply how Windows 11 displays file sizes, and understanding the difference between the two values will clear up the confusion.

Why the Numbers Look Wrong

Windows 11 shows two separate size values when you check the properties of a file or folder:

Size — The full, uncompressed size of the file or folder, including content that has not been downloaded to your device.
Size on disk — The space the file or folder actually occupies on your local drive right now.

In earlier versions of Windows only one size figure was shown, which represented the space used on disk. Windows 11 added the second listing, so the much larger Size number can appear alarming at first glance. This is especially noticeable for directories that are not currently synced locally, because the full cloud size is reported even though little or nothing is stored on the machine.

How to Check the Two Values

Open File Explorer and navigate to the OneDrive or SharePoint folder you want to check.
Right-click the file or folder and select Properties.
On the General tab, locate the Size field and the Size on disk field.
Compare the two values. If the folder is not fully synced to your device, Size on disk will be significantly smaller than Size.
Use Size on disk as the true measure of local storage consumed by that file or folder.

Still Have Questions?

If you are unsure whether your storage usage is normal or you suspect a separate issue with your OneDrive or SharePoint sync, contact the ACS support team for assistance.

Common questions

Why does OneDrive show a file size larger than my entire hard drive?

Windows 11 displays two size values: ‘Size,’ which reflects the full size of all content including unsynced cloud files, and ‘Size on disk,’ which shows only what is stored locally. The ‘Size’ figure can appear much larger than your disk capacity because it includes files that live in the cloud and have not been downloaded to your device.

Is there something wrong with my OneDrive sync if the sizes do not match?

No. A difference between ‘Size’ and ‘Size on disk’ is expected behavior in Windows 11, particularly for folders that are not fully synced locally. It does not indicate an error or a problem with your OneDrive or SharePoint configuration.

Does this also affect SharePoint files synced to my computer?

Yes. The same two-value size display applies to SharePoint files synced through OneDrive on Windows 11, and the same explanation holds: ‘Size on disk’ reflects actual local storage use, while ‘Size’ reflects the full size of the content regardless of sync status.