Storage Sizing Calculator
Estimate usable, raw, and purchased storage across multiple workloads — with GFS retention, RAID sizing, growth projection, and cost estimates.
Plan storage for backups, logs, and general data retention across multiple workloads. Add a line item per data source, pick flat or GFS retention, choose replica or RAID redundancy, then get usable, compressed, raw, and purchased capacity — plus drive counts, cost estimates, and a multi-year growth projection.
Everything runs in your browser and saves automatically. Use Share link to send a client the exact scenario, or Export to keep a copy.
Results
Total usable data
0 TB
Before compression
After compression
0 TB
Per-item ratios applied
Raw capacity
0 TB
After redundancy
Suggested purchase
0 TB
Includes growth buffer
Drives needed
—
At selected drive size
On-prem hardware
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At $/TB rate
Cloud equivalent
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Monthly, tiered
| Line item | GB/day | Retention (days) | Usable | Compression | Compressed |
|---|
| Year | Projected purchased capacity |
|---|
How to interpret this
Usable is the data you actually keep (daily volume × retention). Compressed applies each item's compression/dedup ratio. Raw adds redundancy — either a replica factor or the drive count a RAID level needs. Purchased adds your growth buffer on top.
GFS retention counts daily snapshots as 1 day each, monthly as 30 days, and yearly as 365 days. RAID 10 uses half the drive count for capacity; RAID 5/6 lose one/two drives to parity.
Cloud comparison prices the compressed stored data across hot/cool/archive tiers — useful for a hybrid on-prem vs. cloud conversation. Treat all outputs as a planning baseline, then refine with measured compression ratios and real drive pricing.