Backup Storage Calculator

Estimate backup capacity using the same planning shape Synology describes for retained versions: source data plus changed data across versions, reduced by deduplication and compression savings, then padded with a safety reserve so the result is usable for real-world capacity planning.

Recommended Capacity 0 GB

Planning Inputs

Start with protected source size, then layer in version retention, average change rate, and expected savings.

Protected Source Data Current footprint before optimization

Retained Versions

Average Change Per Version

Deduplication + Compression Savings

Safety Reserve

How Many Backup Copies? Useful when planning 3-2-1 style capacity

Quick Presets Fast starting points for common environments

Source Data

0 GB

The full protected data set before versioning or savings.

Version Delta Storage

0 GB

Estimated changed data kept across retained versions after the first full backup.

Raw Retained Backup

0 GB

Source data plus retained changed data before optimization.

Optimized Storage Need

0 GB

After applying deduplication and compression savings.

Recommended Capacity

0 GB

Optimized storage plus your safety reserve.

Total for All Copies

0 GB

Recommended capacity multiplied by the number of backup copies.

Calculation Model

This page follows the same planning idea Synology documents: one full protected dataset plus retained changed data for additional versions, then storage savings, then a practical reserve.

Capacity Shape

The bars below make it easy to see whether your result is being driven more by source size, retention policy, or protective headroom.

Source Data 0 GB

Retained Change Data 0 GB

Recommended Capacity 0 GB

Planning Notes

Reference

Based on Synology's storage sizing guidance for backup retention and optimization. Source: Synology Knowledge Center

This is still an estimate. Actual usage depends on workload type, churn rate, retention policy, compression efficiency, and how much data is truly unique between versions and devices.