IBackup Professional provides versioning capability up to 30 versions for a single file. It calculates the total storage space only for the latest version of any file and not for the previous versions. For a typical account, this means that you nearly get an overall storage capacity that may be twice or higher the storage capacity you opt for.

If your usage exceeds the opted storage plan, there is no need to necessarily upgrade to the next higher plan. You will be charged for over usage at the rate of USD 2 per GB for a month.