Calculator inputs
Example data table
| Scenario | Change Rate (GB/hr) | Backup (min) | Lag (min) | Worst Loss (GB) | Expected Loss (GB) |
|---|---|---|---|---|---|
| Small CMS | 0.8 | 120 | 0 | 1.6 | 0.8 |
| API + Queue | 6.5 | 60 | 5 | 7.0 | 3.5 |
| Analytics Ingest | 18 | 30 | 10 | 12.0 | 6.0 |
These are illustrative scenarios. Your environment and controls may differ.
Formula used
Data change rate (GB/hour) comes from either:
- GB/hour (direct input), or
- (transactions/hour × KB/transaction) ÷ 1,048,576.
Base RPO window (minutes)
baseRPO = backupInterval + replicationLag
Loss window (minutes)
- Sudden failure: worst = baseRPO
- Silent / ransomware-like: worst = baseRPO + detectionDelay
- If random timing is enabled: expected = baseRPO/2 (+ detectionDelay when applicable)
Data loss (GB)
lossGB = rateGBperHour × (lossMinutes ÷ 60)
Cost impact
- downtimeHours = detectionDelay/60 + restoreHours
- downtimeCost = downtimeHours × costPerHour
- recreateCost = lossGB × recreateCostPerGB
- totalCost = downtimeCost + recreateCost + fixedCost
- annualExpected = expectedTotalCost × incidentsPerYear × probability%
How to use this calculator
- Enter your workload name and stored data size (optional).
- Pick an input method and provide churn values.
- Set backup interval and replication settings.
- Choose the incident type and typical detection delay.
- Add restore time and cost assumptions for your environment.
- Click Calculate to see worst-case and expected results.
- Export CSV or PDF to compare scenarios.
FAQs
1) What does this calculator estimate?
It estimates worst-case and expected data loss based on change rate and recovery windows. It also estimates downtime and data recreation costs, producing a single impact view for planning.
2) Why is detection delay included for some incidents?
Silent corruption and ransomware-like events can keep damaging data until you notice and stop them. Adding detection delay approximates that extra exposure beyond the last restore point.
3) Should I use worst-case or expected loss?
Use worst-case for strict risk tolerance and contractual targets. Use expected loss for budgeting and comparing control improvements under normal assumptions.
4) How do I find an accurate change rate?
Use storage metrics, database write logs, object change events, or application throughput. Start with a conservative estimate, then refine using observed hourly peaks and typical baselines.
5) What does “Base RPO” represent?
It represents the time between the last clean recoverable point and the failure moment, based on backup spacing and any replication lag. Smaller values generally reduce loss exposure.
6) How is annualized expected cost calculated?
It multiplies expected total cost by incidents per year and by the probability that an incident causes unrecoverable loss. This is a planning heuristic, not a guarantee.
7) What’s a practical way to reduce the result?
Shorten backup intervals, reduce asynchronous lag, improve monitoring to shrink detection time, and test restores to reduce recovery time. Layering controls often yields the largest improvement.
8) Are exports identical to on-screen results?
Yes. Exports use the last calculated scenario stored in your session. If you change inputs, recalculate before downloading to ensure the files reflect the newest scenario.
Disclaimer: This tool provides planning estimates. Always validate recovery objectives through testing and incident drills.