What is a typical database compression ratio?

Most general-purpose backup tools achieve 1.5:1 to 3:1 compression on relational databases. Text-heavy schemas (logs, documents) compress more — up to 5:1. Already-compressed binary data (BLOBs, encrypted columns) may yield only 1.1:1. Check your backup software docs or run a test backup to measure.

Why are incremental backups so much smaller?

An incremental backup captures only the pages or blocks changed since the last backup. For a typical OLTP database with a 1–5% daily change rate, incrementals are 1–5% the size of a full backup, which lets you keep much more granular restore points without proportional storage cost.

How do I choose a retention period?

Retention is driven by your Recovery Point Objective (RPO) and compliance requirements. Regulatory frameworks like HIPAA, SOX, and PCI-DSS mandate specific minimum periods. Operationally, 7–30 days of full backups covers most accidental-deletion scenarios; many teams keep 90 days of incrementals for point-in-time recovery.

Does this include transaction log backups?

The incremental backup tier is a proxy for log or differential backups. Enter log backup frequency as your incremental frequency and estimate log size as a percentage of the full database size using the incremental change rate field.

Is my data sent to any server?

No. All calculations run entirely in your browser with JavaScript. Nothing is transmitted.

How accurate are these estimates?

Estimates assume a constant change rate and consistent compression. Real-world storage varies with workload spikes, schema changes, and backup software behavior. Add a 20–30% buffer for production planning.

Backup Storage Calculator

Enter your database size, backup schedule, retention window, and compression ratio to estimate total backup storage needed.

Database & Backup Settings

Database Size

Full Backup Frequency

Full Backup Retention (days)

Incremental Backup Frequency

Daily Change Rate (%)

Percentage of database modified per day (typical: 1–10%)

Incremental Backup Retention (days)

Compression Ratio

2 = 50% size reduction; 1 = no compression

Quick Examples

Fill in your backup settings and click Calculate

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Summary

The Backup Storage Calculator estimates how much disk space your database backup strategy will consume. Enter the database size, how often you run full and incremental backups, how many days you keep them, and the compression ratio your backup tool achieves. The calculator outputs total raw storage, compressed storage, and a per-tier breakdown so you can right-size your backup volume or cloud bucket before provisioning.

How it works

Enter your current database size (in MB, GB, or TB).
Set the full backup frequency — daily, weekly, or monthly.
Set the incremental backup frequency (hourly, daily, or none).
Enter your retention period in days for full and incremental backups.
Enter the compression ratio your backup tool achieves (e.g. 2 means 50% size reduction).
The calculator shows total uncompressed storage, compressed storage, and a tier breakdown.

Use cases

Size a backup volume or NAS before provisioning.
Estimate monthly S3/GCS/Azure Blob costs for backup retention.
Compare storage impact of daily vs. weekly full backup schedules.
Evaluate how much incremental backups add versus full backups alone.
Plan storage capacity when migrating a backup strategy to a new DR site.
Justify a longer or shorter retention window to stakeholders using concrete numbers.
Check whether a 2:1 vs. 4:1 compression ratio meaningfully changes storage costs.
Audit backup storage budget during annual infrastructure reviews.

Frequently Asked Questions

Last updated: 2026-06-11 · Reviewed by Nham Vu