Tech calculator
RAID Capacity Calculator
Compare raw and usable storage for common RAID layouts.
Usable capacity
6 TB
How the raid capacity calculator works
Estimate usable RAID capacity from drive count, drive size, and RAID level.
Four 2 TB drives provide 6 TB usable in RAID 5 before filesystem overhead.
Assumptions and limitations
All drives are treated as equal to the entered smallest-drive capacity. RAID is not a backup, and formatted capacity will be lower.
Inputs and results stay in your browser. Blank, invalid, or mathematically undefined inputs show a clean placeholder instead of a broken number.
Practical use
Use this tech calculator to explore scenarios quickly, then verify important decisions against the original source data or requirements.
Frequently asked questions
Does the raid capacity calculator send my data anywhere?
No. It runs client-side in your browser and makes no network requests.
Why is the result blank or shown as a dash?
One or more inputs are blank, outside the accepted range, or would make the calculation undefined. Check the labels and enter finite values.
Can I use decimal values?
Yes, where decimals are meaningful. Counts that represent whole items may require integers.