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Backup Recovery Calculator

Check whether a restore meets its RTO: backup chain length, restore throughput, parallel streams, verification and infrastructure rebuild.

About Backup Recovery Calculator

A restore reads more than the protected volume: a full backup plus every incremental in the chain, each of which must be applied in order. Aggregate throughput is the per-stream rate times the number of streams the source and target can genuinely sustain in parallel, and the clock starts at infrastructure rebuild — not at the moment data starts moving — because on a real disaster there is nothing to restore onto yet. Most organisations discover their RTO is fiction during the first real restore, because the plan counted data-copy time and forgot the chain, the rebuild and the verification.

Formulas

Backup Recovery

volumeRead = fullBackup × (1 + incrementals × incrementalShare); restoreTime = volumeRead ÷ (perStreamRate × streams); total = rebuild + restore + verification.

incrementalShare
Size of one incremental relative to the full backup
streams
Concurrent restore jobs the target and source can sustain
rebuild
Time to provision hosts, storage and networking before data can land

RTO margin

margin = rtoTarget − totalRecoveryTime; a negative margin means the RTO is aspirational, not achievable.

rtoTarget
Recovery time objective agreed with the business

Worked example

With the default values below, Backup Recovery Calculator returns Total Recovery Time of 27.81. Change any input above and every figure here is recalculated in your browser.

Inputs used

Data to restoreaccepts 0.01–100,000 TB
40 TB
Restore throughput per streamaccepts 1–20,000 MB/s
400 MB/s
Parallel restore streamsaccepts 1–256 streams
4 streams
Incrementals since the last fullaccepts 0–365 increments
6 increments
Each incremental as a share of the fullaccepts 0–100 %
8 %
Infrastructure rebuild before restore startsaccepts 0–720 hours
3 hours
Share of restored data verifiedaccepts 0–100 %
100 %
Verification throughputaccepts 0.05–20 GB/s
1.2 GB/s
RTO targetaccepts 0.25–8,760 hours
24 hours

Results

Total Recovery Time
27.81 hours
Data Restore Time
10.78 hours
Verification Time
14.03 hours
Aggregate Restore Rate
1,600 MB/s
Volume Actually Read
59.20 TB
Margin Against RTO
-3.81 hours
RTO Verdict
Misses RTO — add streams, shorten the incremental chain or pre-stage a warm copy

Step by step

  1. 1Values used
  2. 2Backup Recovery
  3. 3RTO margin
  4. 4Total Recovery Time= 27.81 hours
  5. 5Data Restore Time= 10.78 hours
  6. 6Verification Time= 14.03 hours
  7. 7Aggregate Restore Rate= 1,600 MB/s
  8. 8Volume Actually Read= 59.20 TB
  9. 9Margin Against RTO= -3.81 hours

Assumptions and limits

  • The result is derived only from the 9 inputs listed above. Anything not among them is not part of the calculation.
  • In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
  • Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

How is Backup Recovery calculated?

volumeRead = fullBackup × (1 + incrementals × incrementalShare); restoreTime = volumeRead ÷ (perStreamRate × streams); total = rebuild + restore + verification. A restore reads more than the protected volume: a full backup plus every incremental in the chain, each of which must be applied in order. Aggregate throughput is the per-stream rate times the number of streams the source and target can genuinely sustain in parallel, and the clock starts at infrastructure rebuild — not at the moment data starts moving — because on a real disaster there is nothing to restore onto yet.

Why does Backup Recovery matter?

Most organisations discover their RTO is fiction during the first real restore, because the plan counted data-copy time and forgot the chain, the rebuild and the verification.

What values do I need to enter?

This calculator takes 9 inputs: Data to restore, Restore throughput per stream, Parallel restore streams, Incrementals since the last full, Each incremental as a share of the full, Infrastructure rebuild before restore starts, Share of restored data verified, Verification throughput, RTO target. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.

Why does a long incremental chain hurt so much?

Each incremental has to be read and applied in sequence, so a 30-day chain at 8% each means reading 3.4× the protected volume. Synthetic fulls or periodic full backups collapse the chain and cut restore time proportionally.

Can I skip verification to hit the RTO?

You can, but you are then declaring service restored without knowing whether the data is intact — and after ransomware you also do not know whether you restored the encrypted or backdoored copy. Verifying a sample of critical datasets is the usual compromise.

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Backup Recovery Calculator – Calculate Total Recovery Time