Calculator Inputs
Example Data Table
These sample scenarios illustrate how standby mode and testing frequency influence total costs.
| Scenario | Primary GB | Replica Factor | Standby | Tests/Year | Estimated Monthly (USD) |
|---|---|---|---|---|---|
| Cold + quarterly drills | 2048 | 2× | Cold | 4 | ~ 260–420 |
| Warm + quarterly drills | 2048 | 2× | Warm | 4 | ~ 600–1,050 |
| Hot + monthly drills | 2048 | 3× | Hot | 12 | ~ 1,450–2,900 |
Formula Used
- ReplicaGB = PrimaryGB × (ReplicationFactor − 1)
- StorageMonthly = (PrimaryGB + ReplicaGB) × RegionMultiplier × StorageRate
- RetentionFactor = 1 + (RetentionDays/30) × (SnapshotOverhead%/100)
- BackupMonthly = BackupGB × RegionMultiplier × BackupRate × RetentionFactor (if enabled)
- StandbyComputeMonthly = StandbyHours × ComputeRate × ModeMultiplier × WarmHotMultiplier × RegionMultiplier
- EgressMonthly = MonthlyEgressGB × EgressRate × RegionMultiplier
- TestingMonthly = (AnnualTestCompute + AnnualTestEgress) / 12
- TotalMonthly = (Subtotal + Support + Contingency) − Discount
How to Use This Calculator
- Enter your protected dataset size and replication factor.
- Provide storage, backup, and transfer rates from your provider quotes.
- Select standby mode to reflect your recovery time objectives.
- Model testing frequency and duration to include drill overhead.
- Add tooling, support, contingency, and any negotiated discounts.
- Click Calculate to view results above the form.
- Download a CSV for spreadsheets or a PDF for approvals.
For best results, run at least three scenarios: cost-optimized, balanced, and fastest recovery.
Cost Drivers in Disaster Recovery Budgets
In most cloud environments, storage replication and standby compute dominate recurring DR spend. Storage rises linearly with protected GB and replicas, while compute rises with always-on hours and your selected standby mode. Data transfer becomes material during frequent failovers, cross-region sync, or large validation restores. Tooling fees and operational overhead often appear small individually, but they compound across teams, environments, and compliance needs.
Standby Strategy and Recovery Objectives
Cold standby minimizes cost by keeping only essential components ready, but may miss aggressive RTO targets. Warm standby typically runs a partial stack, reducing recovery time while controlling compute burn. Hot standby keeps a full stack active, enabling rapid cutover at the highest compute cost. Use the standby hours and multipliers to reflect real service footprints, not only VM runtime.
Replication, Backups, and Retention Effects
Replication factor approximates additional copies beyond the primary dataset. Backups add another layer for point-in-time recovery, and retention influences how long those restore points accumulate. The retention factor in this calculator scales backup cost using retention days and snapshot overhead as a planning proxy for change rate. If your data churn is high, retention can quickly outpace baseline storage rates.
Testing, Validation, and Hidden Monthly Spend
DR testing is essential for readiness, but it introduces predictable spikes: extra compute for full-scale drills and extra transfer when validating restores or moving traffic. This estimator converts annual drill activity into a monthly equivalent so budgets remain comparable across teams. Increasing tests from quarterly to monthly can materially raise annual cost even when production settings remain unchanged.
Benchmarking and Scenario Planning Workflow
Start with a baseline scenario using current rates and a realistic standby mode. Then run a “fastest recovery” scenario by increasing standby intensity, replication, and test frequency. Finally, run a “cost-optimized” scenario by reducing standby mode, limiting egress, and tuning retention. Compare the monthly breakdown lines to identify which levers drive savings without compromising required RPO/RTO commitments.
FAQs
1) What does the replication factor represent?
It models how many total copies exist for your protected dataset. A factor of 2 means one additional replica beyond primary. A factor of 3 means two replicas. It is a storage planning simplification and may differ from service-specific implementations.
2) How should I choose cold, warm, or hot standby?
Choose based on recovery time targets and operational complexity. Cold is lowest cost but slower. Warm balances speed and spend. Hot is fastest but expensive. Validate with business RTO/RPO and the real services you must keep running.
3) Why is retention modeled with a “snapshot overhead” percentage?
Snapshot overhead approximates how much data changes between restore points. Higher churn increases retained deltas and effective backup footprint. The model scales backup cost using retention days and overhead to support quick what-if comparisons when exact backup accounting is unavailable.
4) Does the calculator include failover downtime costs?
No. It estimates infrastructure and operational run-rate costs for DR capability. Business impact, revenue loss, penalties, and customer support surge costs are separate. You can use the results here as the technical cost input to a broader risk model.
5) How do I model enterprise discounts or reserved capacity?
Apply your negotiated discount percentage to reflect committed-use pricing, reserved instances, or contractual credits. If discounts vary by service, run multiple scenarios: one with blended discount and another with conservative assumptions to bracket uncertainty during budgeting.
6) What is a good testing frequency for DR drills?
Many teams start quarterly for major cutover drills and add smaller monthly validations for backups and runbooks. The right frequency depends on change rate, compliance requirements, and incident history. Use the testing inputs to quantify readiness improvements versus cost.