The base assumption in the calculator is that you keep your daily/weekly backups — both full and incremental images — for some portion of 3 months (4 weeks = 1 month, 8 weeks = 2 months, 12 weeks = 3 months).

In addition to the above retention, we are using general case industry retention levels to include month-end backups for 1 year, quarter-end backups for 2 years and year-end backups for 3 years.