

OneDrive does not allow upload of files larger than 100MB (files not uploaded because of that are here.For example, if you have two PDF files in a OneDrive folder and they have exactly the same content, they will use storage on one file. When downloaded, the files are of their correct size. OneDrive de-duplicates some files so they take less space in OneDrive.MS Office files in Google Drive take their full size while OneDrive will store these files in MS Office format and compress them (so they will use a fraction of the storage space than on Google Drive).Google Drive does not count files which are in Google Docs format against your storage quota.Google Drive counts versions of files against your storage quota (i.e., if a file is changed twice then it will use double of quota than a file that was changed just once).Google Drive counts files in the trash against your storage quota.

Google Drive and OneDrive have different storage sizes because they calculate storage usage quite differently.
