Aisha K.
Mar 12, 2026
Clean layout and the results update instantly. Exactly what I needed for a quick planning check.
Networking & IT Infrastructure
RAID Calculator — Usable Capacity, Fault Tolerance & Speed
RAID 0: n×cap; RAID 1: cap; RAID 5: (n−1)×cap; RAID 10: (n/2)×cap.
Estimate usable capacity and fault tolerance across common RAID levels. Planning estimates only — verify with production tools and vendor pricing where applicable.
Inputs
224
0.520
010
Smart analysis
Recommendations
Tailored to your live inputs and result—guidance only, not professional advice.
- Interpret
Treat this as a planning estimate
Primary result: Usable capacity = 8.0 TB. Re-run with optimistic and pessimistic inputs to understand the range—not just a single point.
Scenario studio
Compare A vs B
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Scenario A
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Scenario B
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Plain-English guide
Terms & how it works
Confused by a field? Read the short definitions here while you use the tool.
Number of drives
The “Number of drives” value used in this tool’s formula. Adjust it to see results update live.
Drive size (TB each)
The “Drive size (TB each)” value used in this tool’s formula. Adjust it to see results update live.
RAID level (0, 1, 5, or 10)
The “RAID level (0, 1, 5, or 10)” value used in this tool’s formula. Adjust it to see results update live.
How this calculator works
Estimate usable capacity and fault tolerance across common RAID levels. Planning estimates only — verify with production tools and vendor pricing where applicable. RAID 0: n×cap; RAID 1: cap; RAID 5: (n−1)×cap; RAID 10: (n/2)×cap. Example: 4 × 4 TB drives, RAID 10 → 8 TB usable, 1 disk failure tolerance.
RAID 0: n×cap; RAID 1: cap; RAID 5: (n−1)×cap; RAID 10: (n/2)×cap.
Example: 4 × 4 TB drives, RAID 10 → 8 TB usable, 1 disk failure tolerance.
When to use this RAID
Common use cases
- Estimate usable capacity and fault tolerance across common RAID levels.
- Sanity-check with this case: 4 × 4 TB drives, RAID 10 → 8 TB usable, 1 disk failure tolerance.
- The relationship is: RAID 0: n×cap; RAID 1: cap; RAID 5: (n−1)×cap; RAID 10: (n/2)×cap.
Localized examples
- Networking & IT Infrastructure: the example on this page uses the same formula as the widget.
What you get
- Fields: Number of drives, Drive size (TB each), RAID level (0, 1, 5, or 10)
- RAID 0: n×cap; RAID 1: cap; RAID 5: (n−1)×cap; RAID 10: (n/2)×cap.
- Example on the page: 4 × 4 TB drives, RAID 10 → 8 TB usable, 1 disk failure tolerance.
How to Calculate RAID Step-by-Step
- 1Enter Number of drives, Drive size (TB each), RAID level (0, 1, 5, or 10). Use the values you have, not a catalog average, unless that is all you know.
- 2RAID 0: n×cap; RAID 1: cap; RAID 5: (n−1)×cap; RAID 10: (n/2)×cap.
- 3Worked case: 4 × 4 TB drives, RAID 10 → 8 TB usable, 1 disk failure tolerance.
- 4Compare the result to last month’s invoice or a vendor calculator before you commit capacity.
Governing formula
RAID 0: n×cap; RAID 1: cap; RAID 5: (n−1)×cap; RAID 10: (n/2)×cap.
4 × 4 TB drives, RAID 10 → 8 TB usable, 1 disk failure tolerance.
Example: set Number of drives = 4, Drive size (TB each) = 4, RAID level (0, 1, 5, or 10) = 10, then read the result.
Variable definitions
- driveCount
Number of drives
The “Number of drives” field. Default 4; typical range 2–24.
- driveSizeTb
Drive size (TB each)
The “Drive size (TB each)” field. Default 4; typical range 0.5–20.
- raidLevel
RAID level (0, 1, 5, or 10)
The “RAID level (0, 1, 5, or 10)” field. Default 10; typical range 0–10.
- Closed-form math (RAID 0: n×cap; RAID 1: cap; RAID 5: (n−1)×cap; RAID 10: (n/2)×cap.) misses idle time, egress, packet loss, and reserved capacity on the real bill.
- Nothing here is uploaded for the calculation itself.
Frequently Asked Questions
RAID 0: n×cap; RAID 1: cap; RAID 5: (n−1)×cap; RAID 10: (n/2)×cap.
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Community
Reviews & Ratings
See what others think about this tool, then leave your own rating to help improve CalculioHub.
4.8
out of 5.0
4 reviews
Daniel R.
Feb 28, 2026
Very usable on mobile. Would love a save/export option later, but the math feels solid.
Priya S.
Feb 3, 2026
The FAQ section answered my questions before I even had to search. Smooth dark mode too.
Marcus L.
Jan 19, 2026
Simple inputs, clear outputs. This replaced three bookmarks I used to juggle.
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