# Synology RAID / SHR Calculator: Usable Capacity Planner

Canonical: https://cloudzat.com/synology-raid-shr-calculator/
Full Markdown: https://cloudzat.com/synology-raid-shr-calculator/index.md
Cluster context: https://cloudzat.com/ai/synology-technical/context.json

Purpose: Estimate usable capacity for SHR-1, SHR-2, RAID 1, RAID 5 and RAID 6 with equal or mixed drive sizes, redundancy and expansion headroom.
Direct answer: Enter the actual capacities you plan to install. A mixed-drive SHR set can sometimes use capacity that RAID 5 or RAID 6 leaves idle, but unmatched top portions still remain unavailable until enough larger drives exist to form a protected region.

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