Hosting

Backup Retention Calculator

Estimate backup storage volume from backup size, frequency, and retention period.

Last reviewed: April 30, 2026Free toolMethodology

Backup Retention Calculator

These fields start with sample inputs. Keep them or replace them, then run the tool to show a fresh result.

Number fields accept plain values and common formatted input such as 250000, 250,000, or 1,234.56.

Result

Calculating the sample result.

Why it matters

Backup policies seem cheap until retained copies start compounding against storage pricing and recovery requirements.

When to use

  • Sizing backup buckets or volumes
  • Comparing retention policy changes
  • Estimating recovery storage cost

Inputs & Outputs

Inputs

  • Backup size is the average size of one backup copy.
  • Backups per week is the number of copies created each week.
  • Retention weeks defines how long those copies are kept.

Outputs

  • Stored backup volume shows the retained data footprint under the policy.
  • Monthly and annualized storage summaries help with budget planning.

Retention footprint method

Multiply average backup size by the number of backups created during the retention window.

Retained backup volume = backup size x backups per week x retention weeks

Worked example

1

Backup policy check

A database backup averages 180 GB, runs 7 times per week, and is retained for 8 weeks.

Inputs

  • Backup size: 180 GB
  • Backups per week: 7
  • Retention: 8 weeks

Steps

  • Copies retained = 7 x 8 = 56
  • Stored volume = 180 x 56 = 10,080 GB

Result

  • The policy retains about 10.08 TB of backup data.

Edge cases & caveats

  • Incremental and deduplicated backups can reduce real storage usage materially.
  • Compression, lifecycle rules, and cross-region copies are not modeled here.

Frequently Asked Questions

Should I use full backup size or incremental size?

Use the effective average size that most closely reflects how your provider bills stored backup data.

Can I use this for log archives too?

Yes, as long as the archive pattern is regular enough to approximate with average size and retention.

Keep going

Related Tools

hosting

Cloud Storage Cost Calculator

Estimate monthly storage cost from stored gigabytes and the provider's per-GB monthly rate.

Open
hosting

Log Storage Calculator

Estimate retained log volume from daily log generation, compression ratio, and retention period.

Open
hosting

Database Storage Calculator

Estimate database storage footprint from row count, average row size, and index overhead.

Open