No. This information isn't readily available from SQL Server. E.g.
For a full backup, a database that's 100 MB in size may only create a 90 MB backup, if the trx log size is 10 MB in size, all data is committed and the simple recovery model is used.
For differential and transaction log backups, there isn't an accurate way to tell how much data needs to be backed up.
Peter Yeoh
SQL Backup Consultant Developer
Associate, Yohz Software Beyond compression - SQL Backup goodies under the hood, updated for version 8
Comments
For a full backup, a database that's 100 MB in size may only create a 90 MB backup, if the trx log size is 10 MB in size, all data is committed and the simple recovery model is used.
For differential and transaction log backups, there isn't an accurate way to tell how much data needs to be backed up.
SQL Backup Consultant Developer
Associate, Yohz Software
Beyond compression - SQL Backup goodies under the hood, updated for version 8