Size a backup set across full and incremental backups with retention.
Retained full backups dominate backup storage, while incrementals are cheap because only changed data is captured. Compression typically removes two-thirds of the volume. Backup storage commonly exceeds the database several times over, which is a cost that surprises teams when retention policies are set without arithmetic.
Database Backup Size
Backup storage = full backups × compressed size + incrementals × daily change size
Backup storage = full backups × compressed size + incrementals × daily change size Retained full backups dominate backup storage, while incrementals are cheap because only changed data is captured. Compression typically removes two-thirds of the volume.
Backup storage commonly exceeds the database several times over, which is a cost that surprises teams when retention policies are set without arithmetic.
This calculator takes 5 inputs: Database size, Backup compression saving, Daily change rate, Full backups retained, Incremental backups retained. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.